fetchPreAuthToken in box too

[mifi]

like all other providers

[github-actions]

Diff output files

diff --git a/packages/@uppy/box/lib/Box.js b/packages/@uppy/box/lib/Box.js
index 15ccffe..2f92b5f 100644
--- a/packages/@uppy/box/lib/Box.js
+++ b/packages/@uppy/box/lib/Box.js
@@ -69,7 +69,7 @@ export default class Box extends UIPlugin {
     this.unmount();
   }
   onFirstRender() {
-    return this.view.getFolder();
+    return Promise.all([this.provider.fetchPreAuthToken(), this.view.getFolder()]);
   }
   render(state) {
     return this.view.render(state);