diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/__mocks__/engine_logic.mock.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/__mocks__/engine_logic.mock.ts
index d16391089120a..23d638d5f25f3 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/__mocks__/engine_logic.mock.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/__mocks__/engine_logic.mock.ts
@@ -12,6 +12,7 @@ import { generateEncodedPath } from '../utils/encode_path_params';
 export const mockEngineValues = {
   engineName: 'some-engine',
   engine: {} as EngineDetails,
+  searchKey: 'search-abc123',
 };
 
 export const mockEngineActions = {
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.test.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.test.ts
index 5435450f1bfdb..836265a037e16 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.test.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.test.ts
@@ -9,6 +9,8 @@ import { LogicMounter, mockHttpValues } from '../../../__mocks__';
 
 import { nextTick } from '@kbn/test/jest';
 
+import { ApiTokenTypes } from '../credentials/constants';
+
 import { EngineTypes } from './types';
 
 import { EngineLogic } from './';
@@ -47,6 +49,7 @@ describe('EngineLogic', () => {
     hasSchemaConflicts: false,
     hasUnconfirmedSchemaFields: false,
     engineNotFound: false,
+    searchKey: '',
   };
 
   beforeEach(() => {
@@ -263,5 +266,57 @@ describe('EngineLogic', () => {
         });
       });
     });
+
+    describe('searchKey', () => {
+      it('should select the first available search key for this engine', () => {
+        const engine = {
+          ...mockEngineData,
+          apiTokens: [
+            {
+              key: 'private-123xyz',
+              name: 'privateKey',
+              type: ApiTokenTypes.Private,
+            },
+            {
+              key: 'search-123xyz',
+              name: 'searchKey',
+              type: ApiTokenTypes.Search,
+            },
+            {
+              key: 'search-8910abc',
+              name: 'searchKey2',
+              type: ApiTokenTypes.Search,
+            },
+          ],
+        };
+        mount({ engine });
+
+        expect(EngineLogic.values).toEqual({
+          ...DEFAULT_VALUES,
+          engine,
+          searchKey: 'search-123xyz',
+        });
+      });
+
+      it('should return an empty string if none are available', () => {
+        const engine = {
+          ...mockEngineData,
+          apiTokens: [
+            {
+              key: 'private-123xyz',
+              name: 'privateKey',
+              type: ApiTokenTypes.Private,
+            },
+          ],
+        };
+        mount({ engine });
+
+        expect(EngineLogic.values).toEqual({
+          ...DEFAULT_VALUES,
+          engine,
+          searchKey: '',
+        });
+      });
+    });
   });
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.ts
index 8fbf45bc85e52..5cbe89b364859 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine/engine_logic.ts
@@ -8,6 +8,8 @@
 import { kea, MakeLogicType } from 'kea';
 
 import { HttpLogic } from '../../../shared/http';
+import { ApiTokenTypes } from '../credentials/constants';
+import { ApiToken } from '../credentials/types';
 
 import { EngineDetails, EngineTypes } from './types';
 
@@ -21,6 +23,7 @@ interface EngineValues {
   hasSchemaConflicts: boolean;
   hasUnconfirmedSchemaFields: boolean;
   engineNotFound: boolean;
+  searchKey: string;
 }
 
 interface EngineActions {
@@ -87,6 +90,14 @@ export const EngineLogic = kea<MakeLogicType<EngineValues, EngineActions>>({
       () => [selectors.engine],
       (engine) => engine?.unconfirmedFields?.length > 0,
     ],
+    searchKey: [
+      () => [selectors.engine],
+      (engine: Partial<EngineDetails>) => {
+        const isSearchKey = (token: ApiToken) => token.type === ApiTokenTypes.Search;
+        const searchKey = (engine.apiTokens || []).find(isSearchKey);
+        return searchKey?.key || '';
+      },
+    ],
   }),
   listeners: ({ actions, values }) => ({
     initializeEngine: async () => {
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.test.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.test.tsx
index b015c2dec6c0a..82b925f57f2df 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.test.tsx
@@ -13,7 +13,9 @@ import { setMockValues, setMockActions } from '../../../../__mocks__';
 
 import React from 'react';
 
-import { shallow } from 'enzyme';
+import { shallow, ShallowWrapper } from 'enzyme';
+
+import { EuiForm } from '@elastic/eui';
 
 import { ActiveField } from '../types';
 import { generatePreviewUrl } from '../utils';
@@ -29,6 +31,7 @@ describe('SearchUIForm', () => {
     urlField: 'url',
     facetFields: ['category'],
     sortFields: ['size'],
+    dataLoading: false,
   };
   const actions = {
     onActiveFieldChange: jest.fn(),
@@ -43,10 +46,6 @@ describe('SearchUIForm', () => {
     setMockActions(actions);
   });
 
-  beforeEach(() => {
-    jest.clearAllMocks();
-  });
-
   it('renders', () => {
     const wrapper = shallow(<SearchUIForm />);
     expect(wrapper.find('[data-test-subj="selectTitle"]').exists()).toBe(true);
@@ -56,6 +55,7 @@ describe('SearchUIForm', () => {
   });
 
   describe('title field', () => {
+    beforeEach(() => jest.clearAllMocks());
     const subject = () => shallow(<SearchUIForm />).find('[data-test-subj="selectTitle"]');
 
     it('renders with its value set from state', () => {
@@ -84,6 +84,7 @@ describe('SearchUIForm', () => {
   });
 
   describe('url field', () => {
+    beforeEach(() => jest.clearAllMocks());
     const subject = () => shallow(<SearchUIForm />).find('[data-test-subj="selectUrl"]');
 
     it('renders with its value set from state', () => {
@@ -112,6 +113,7 @@ describe('SearchUIForm', () => {
   });
 
   describe('filters field', () => {
+    beforeEach(() => jest.clearAllMocks());
     const subject = () => shallow(<SearchUIForm />).find('[data-test-subj="selectFilters"]');
 
     it('renders with its value set from state', () => {
@@ -145,6 +147,7 @@ describe('SearchUIForm', () => {
   });
 
   describe('sorts field', () => {
+    beforeEach(() => jest.clearAllMocks());
     const subject = () => shallow(<SearchUIForm />).find('[data-test-subj="selectSort"]');
 
     it('renders with its value set from state', () => {
@@ -177,26 +180,61 @@ describe('SearchUIForm', () => {
     });
   });
 
-  it('includes a link to generate the preview', () => {
-    (generatePreviewUrl as jest.Mock).mockReturnValue('http://www.example.com?foo=bar');
+  describe('generate preview button', () => {
+    let wrapper: ShallowWrapper;
 
-    setMockValues({
-      ...values,
-      urlField: 'foo',
-      titleField: 'bar',
-      facetFields: ['baz'],
-      sortFields: ['qux'],
+    beforeAll(() => {
+      jest.clearAllMocks();
+      (generatePreviewUrl as jest.Mock).mockReturnValue('http://www.example.com?foo=bar');
+      setMockValues({
+        ...values,
+        urlField: 'foo',
+        titleField: 'bar',
+        facetFields: ['baz'],
+        sortFields: ['qux'],
+        searchKey: 'search-123abc',
+      });
+      wrapper = shallow(<SearchUIForm />);
+    });
+
+    it('should be a submit button', () => {
+      expect(wrapper.find('[data-test-subj="generateSearchUiPreview"]').prop('type')).toBe(
+        'submit'
+      );
+    });
+
+    it('should be wrapped in a form configured to POST to the preview screen in a new tab', () => {
+      const form = wrapper.find(EuiForm);
+      expect(generatePreviewUrl).toHaveBeenCalledWith({
+        urlField: 'foo',
+        titleField: 'bar',
+        facets: ['baz'],
+        sortFields: ['qux'],
+      });
+      expect(form.prop('action')).toBe('http://www.example.com?foo=bar');
+      expect(form.prop('target')).toBe('_blank');
+      expect(form.prop('method')).toBe('POST');
+      expect(form.prop('component')).toBe('form');
     });
 
-    const subject = () =>
-      shallow(<SearchUIForm />).find('[data-test-subj="generateSearchUiPreview"]');
+    it('should include a searchKey in that form POST', () => {
+      const form = wrapper.find(EuiForm);
+      const hiddenInput = form.find('input[type="hidden"]');
+      expect(hiddenInput.prop('id')).toBe('searchKey');
+      expect(hiddenInput.prop('value')).toBe('search-123abc');
+    });
+  });
 
-    expect(subject().prop('href')).toBe('http://www.example.com?foo=bar');
-    expect(generatePreviewUrl).toHaveBeenCalledWith({
-      urlField: 'foo',
-      titleField: 'bar',
-      facets: ['baz'],
-      sortFields: ['qux'],
+  it('should disable everything while data is loading', () => {
+    setMockValues({
+      ...values,
+      dataLoading: true,
     });
+    const wrapper = shallow(<SearchUIForm />);
+    expect(wrapper.find('[data-test-subj="selectTitle"]').prop('disabled')).toBe(true);
+    expect(wrapper.find('[data-test-subj="selectFilters"]').prop('isDisabled')).toBe(true);
+    expect(wrapper.find('[data-test-subj="selectSort"]').prop('isDisabled')).toBe(true);
+    expect(wrapper.find('[data-test-subj="selectUrl"]').prop('disabled')).toBe(true);
+    expect(wrapper.find('[data-test-subj="generateSearchUiPreview"]').prop('disabled')).toBe(true);
   });
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.tsx
index 15bd699be721c..b795a46268237 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/components/search_ui_form.tsx
@@ -11,6 +11,7 @@ import { useValues, useActions } from 'kea';
 
 import { EuiForm, EuiFormRow, EuiSelect, EuiComboBox, EuiButton } from '@elastic/eui';
 
+import { EngineLogic } from '../../engine';
 import {
   TITLE_FIELD_LABEL,
   TITLE_FIELD_HELP_TEXT,
@@ -27,7 +28,9 @@ import { ActiveField } from '../types';
 import { generatePreviewUrl } from '../utils';
 
 export const SearchUIForm: React.FC = () => {
+  const { searchKey } = useValues(EngineLogic);
   const {
+    dataLoading,
     validFields,
     validSortFields,
     validFacetFields,
@@ -70,9 +73,11 @@ export const SearchUIForm: React.FC = () => {
   const selectedFacetOptions = formatMultiOptions(facetFields);
 
   return (
-    <EuiForm>
+    <EuiForm component="form" action={previewHref} target="_blank" method="POST">
+      <input type="hidden" id="searchKey" name="searchKey" value={searchKey} />
       <EuiFormRow label={TITLE_FIELD_LABEL} helpText={TITLE_FIELD_HELP_TEXT} fullWidth>
         <EuiSelect
+          disabled={dataLoading}
           options={optionFields}
           value={selectedTitleOption && selectedTitleOption.value}
           onChange={(e) => onTitleFieldChange(e.target.value)}
@@ -85,6 +90,7 @@ export const SearchUIForm: React.FC = () => {
       </EuiFormRow>
       <EuiFormRow label={FILTER_FIELD_LABEL} helpText={FILTER_FIELD_HELP_TEXT} fullWidth>
         <EuiComboBox
+          isDisabled={dataLoading}
           options={facetOptionFields}
           selectedOptions={selectedFacetOptions}
           onChange={(newValues) => onFacetFieldsChange(newValues.map((field) => field.value!))}
@@ -96,6 +102,7 @@ export const SearchUIForm: React.FC = () => {
       </EuiFormRow>
       <EuiFormRow label={SORT_FIELD_LABEL} helpText={SORT_FIELD_HELP_TEXT} fullWidth>
         <EuiComboBox
+          isDisabled={dataLoading}
           options={sortOptionFields}
           selectedOptions={selectedSortOptions}
           onChange={(newValues) => onSortFieldsChange(newValues.map((field) => field.value!))}
@@ -108,6 +115,7 @@ export const SearchUIForm: React.FC = () => {
 
       <EuiFormRow label={URL_FIELD_LABEL} helpText={URL_FIELD_HELP_TEXT} fullWidth>
         <EuiSelect
+          disabled={dataLoading}
           options={optionFields}
           value={selectedURLOption && selectedURLOption.value}
           onChange={(e) => onUrlFieldChange(e.target.value)}
@@ -119,8 +127,8 @@ export const SearchUIForm: React.FC = () => {
         />
       </EuiFormRow>
       <EuiButton
-        href={previewHref}
-        target="_blank"
+        disabled={dataLoading}
+        type="submit"
         fill
         iconType="popout"
         iconSide="right"
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/i18n.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/i18n.ts
index dfdc1d1db4c39..e26df0bd89832 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/i18n.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/i18n.ts
@@ -7,6 +7,8 @@
 
 import { i18n } from '@kbn/i18n';
 
+import { CREDENTIALS_TITLE } from '../credentials';
+
 export const SEARCH_UI_TITLE = i18n.translate(
   'xpack.enterpriseSearch.appSearch.engine.searchUI.title',
   { defaultMessage: 'Search UI' }
@@ -48,3 +50,9 @@ export const GENERATE_PREVIEW_BUTTON_LABEL = i18n.translate(
   'xpack.enterpriseSearch.appSearch.engine.searchUI.generatePreviewButtonLabel',
   { defaultMessage: 'Generate search experience' }
 );
+export const NO_SEARCH_KEY_ERROR = (engineName: string) =>
+  i18n.translate('xpack.enterpriseSearch.appSearch.engine.searchUI.noSearchKeyErrorMessage', {
+    defaultMessage:
+      "It looks like you don't have any Public Search Keys with access to the '{engineName}' engine. Please visit the {credentialsTitle} page to set one up.",
+    values: { engineName, credentialsTitle: CREDENTIALS_TITLE },
+  });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.test.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.test.ts
index 2191c633131bb..2e29ac0d398a6 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.test.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.test.ts
@@ -18,7 +18,7 @@ import { SearchUILogic } from './';
 describe('SearchUILogic', () => {
   const { mount } = new LogicMounter(SearchUILogic);
   const { http } = mockHttpValues;
-  const { flashAPIErrors } = mockFlashMessageHelpers;
+  const { flashAPIErrors, setErrorMessage } = mockFlashMessageHelpers;
 
   const DEFAULT_VALUES = {
     dataLoading: true,
@@ -35,6 +35,7 @@ describe('SearchUILogic', () => {
   beforeEach(() => {
     jest.clearAllMocks();
     mockEngineValues.engineName = 'engine1';
+    mockEngineValues.searchKey = 'search-abc123';
   });
 
   it('has expected default values', () => {
@@ -155,6 +156,17 @@ describe('SearchUILogic', () => {
         });
       });
 
+      it('will short circuit the call if there is no searchKey available for this engine', async () => {
+        mockEngineValues.searchKey = '';
+        mount();
+
+        SearchUILogic.actions.loadFieldData();
+
+        expect(setErrorMessage).toHaveBeenCalledWith(
+          "It looks like you don't have any Public Search Keys with access to the 'engine1' engine. Please visit the Credentials page to set one up."
+        );
+      });
+
       it('handles errors', async () => {
         http.get.mockReturnValueOnce(Promise.reject('error'));
         mount();
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.ts
index c9e2e5623d9fd..096365f57ea36 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/search_ui_logic.ts
@@ -7,10 +7,12 @@
 
 import { kea, MakeLogicType } from 'kea';
 
-import { flashAPIErrors } from '../../../shared/flash_messages';
+import { flashAPIErrors, setErrorMessage } from '../../../shared/flash_messages';
 import { HttpLogic } from '../../../shared/http';
 import { EngineLogic } from '../engine';
 
+import { NO_SEARCH_KEY_ERROR } from './i18n';
+
 import { ActiveField } from './types';
 
 interface InitialFieldValues {
@@ -84,7 +86,12 @@ export const SearchUILogic = kea<MakeLogicType<SearchUIValues, SearchUIActions>>
   listeners: ({ actions }) => ({
     loadFieldData: async () => {
       const { http } = HttpLogic.values;
-      const { engineName } = EngineLogic.values;
+      const { searchKey, engineName } = EngineLogic.values;
+
+      if (!searchKey) {
+        setErrorMessage(NO_SEARCH_KEY_ERROR(engineName));
+        return;
+      }
 
       const url = `/api/app_search/engines/${engineName}/search_ui/field_config`;
 
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.test.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.test.ts
index 8d99ffc514b3f..9a005649e7dc9 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.test.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.test.ts
@@ -33,7 +33,7 @@ describe('generatePreviewUrl', () => {
         empty2: [''], // Empty fields should be stripped
       })
     ).toEqual(
-      'http://localhost:3002/as/engines/national-parks-demo/reference_application/preview?facets[]=baz&facets[]=qux&sortFields[]=quux&sortFields[]=quuz&titleField=foo&urlField=bar'
+      'http://localhost:3002/as/engines/national-parks-demo/search_experience/preview?facets[]=baz&facets[]=qux&sortFields[]=quux&sortFields[]=quuz&titleField=foo&urlField=bar'
     );
   });
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.ts b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.ts
index 72d90514ea0a0..6c57df0d66a2a 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/search_ui/utils.ts
@@ -15,7 +15,7 @@ export const generatePreviewUrl = (query: ParsedQuery) => {
   return queryString.stringifyUrl(
     {
       query,
-      url: getAppSearchUrl(`/engines/${engineName}/reference_application/preview`),
+      url: getAppSearchUrl(`/engines/${engineName}/search_experience/preview`),
     },
     { arrayFormat: 'bracket', skipEmptyString: true }
   );