Google Play Games server side access

       PlayGamesPlatform.Activate();
        PlayGamesPlatform.Instance.Authenticate(ProcessAuthentication);
    }
    internal void ProcessAuthentication(SignInStatus status)
    {
        if (status == SignInStatus.Success)
        {
            PlayGamesPlatform.Instance.RequestServerSideAccess(true, code =>
            {
                authCode = code;

I get the server access token and this used to work 6 months ago but now when I put the token into
https://oauth2.googleapis.com/tokeninfo?id_token=
It keeps saying Invalid Token
The php file i send the token to also comes up with an error.
Is there something I am doing wrong to get the wrong code?

This isn’t really a Unity issue, it only concerns your server and Google Play. Goolge’s help resources would be a better place to bring this up.

The most likely explanation is that the token expired or was revoked. Do you have a process in place to refresh the token before it expires? You should also gracefully handle invalid tokens and force a re-authentication in the app, to properly handle the token getting revoked.