FreshRSS with OAuth2/OpenID auth show 'NOT FOUND' error

[EXREY]

I'm running Authentik 2024.12.2 and FreshRSS behind Traefik in docker container, other apps using proxy provider just works fine.

https://docs.goauthentik.io/integrations/services/freshrss/
I follow the instruction above to create a application like this:

And then create a OAuth2/OpenID Provider like this:

And add these environments into FreshRSS container:

Then the FreshRSS website shows a 'NOT FOUND' error:

Does anyone have any idea to solve this?
Thanks a lot.