Implementing Google-OAuth with expo-auth-session is quite problematic and will lead you to all sorts of redirect URI and authorization errors (I have had the same issue before). Instead, I recommend using @react-native-google-signin/google-signin which is also what Expo Documentation recommends as well for a more streamlined and issue-free experience. However, for this method you will require a dev build (EAS build recommended) and some setup (on the documentation page).