So as a brief description of my env.
Behind a Nginix Proxy Manager container is the Authentik container and my service I wish to add openid to, Photoprism.
In Authentik I have a simple authentication flow that the group 'Photo Admin' (That my user is in). A OAuth2/OpenID Provider set to my flow with implicit authorization. When I go from photoprism to authenticate I get a 404 at /application/o/authorize/ (trailing slash is present). Im guessing a header issue potently but ive tried about anything I can think of.