I have spent countless hours trying to authenticate with Google through those two calls but I always get NOTAUTHENTICATED response. I have triple checked my app id, my client id, and my client secret but still can't get this to work. Has anyone been able to correctly implement either of these calls? I am starting to think the issue is on Gamesparks backend...

Thank you for your response, but I use PlayFab now. I used the same configuration and it just worked.

We successfully use GooglePlayConnectRequest daily for players.  Yes - it was difficult to get configured (most of the difficulty was/is navigating the google side of the setup and the Google API hell)

Hello, did you made any progress with this issue?