[Bug] appflowy not work with authentik

[anschein]

I'm trying to use authentik as a saml provider, authentik is a third party open source authentication system that works well with my other services, I also checked the saml output endpoints of authentik and it is able to generate the xml metadata correctly, but I'm populating the metadata address into appflowy The following error is thrown when adding the saml provider:

2024-12-21T04:17:40Z INF component=api error=400: HTTP 406 error fetching SAML Metadata from URL 'https://example.com/api/v3/providers/saml/8/ metadata/' method=POST msg=400: HTTP 406 error fetching SAML Metadata from URL 'https://example.com/api/v3/providers/saml/8/metadata/' path=/ admin/sso/providers referer=appflowy-flutter:// remote_addr=172.30.0.10 request_id=ad452403-acaf-48f0-9897-962aa9343cbd

The xml output of the authentik endpoint is as follows:

{"metadata":"<md:EntityDescriptor xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" xmlns:ds="http://www.w3.org/2000/09/xmldsig#\" xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" xmlns:xenc="http://www.w3.org/2001/04/xmlenc#\" ID="_19222da8cefbc5daf734bef3c753f512a48a21b0581f1dd6778fa7dd43e1d57d" entityID="authentik"><md:IDPSSODescriptor protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol"><md:SingleLogoutService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="https://example.com/application/saml/appflowy/slo/binding/redirect/\"/><md:SingleLogoutService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://example.com/application/saml/appflowy/slo/binding/post/\"/>md:NameIDFormaturn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress</md:NameIDFormat>md:NameIDFormaturn:oasis:names:tc:SAML:2.0:nameid-format:persistent</md:NameIDFormat>md:NameIDFormaturn:oasis:names:tc:SAML:1.1:nameid-format:X509SubjectName</md:NameIDFormat>md:NameIDFormaturn:oasis:names:tc:SAML:2.0:nameid-format:transient</md:NameIDFormat><md:SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="https://example.com/application/saml/appflowy/sso/binding/redirect/\"/><md:SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://example.com/application/saml/appflowy/sso/binding/post/\"/></md:IDPSSODescriptor></md:EntityDescriptor>"}