I'm trying to follow the instructions at: https://developers.google.com/identity/sign-in/ios/offline-access. Whenever I send a token I get: "redirect_uri_mismatch".
I read in another question that client ids need to wait for a bit. This is not the case. The backend id has been active since August. The web app works fine. The server json sets "redirect_uris" to "postmessage".
This looks very similar to the question: Cross-platform Google OAuth Signin: redirect_uri mismatch but my scenario is with iOS and Go.
If I add a scope "audience:server:client_id:" as suggested by https://developers.google.com/identity/protocols/CrossClientAuth I get an "invalid scope" error.