TL;DR of the article, generated automatically.

Google released a free, open-source Sign in with Google plugin for Unity, for Android and iOS.

• Unity: supports Unity 6.5. Replaces an older version with compatibility issues.
• Setup: enter your Web Client ID and iOS Reversed Client ID in the Unity Editor.
• Backends: returns a Google ID token for Firebase, Supabase, Auth0 or your own server.