title: Get user's birthday/gender using Google Sign-In in Flutter
body: <p>I want to get user's birthday and gender using Firebase Auth and Google Sign-In. Unfortunately, after the login happens, I am getting only the user's email, display name, photo url and phone number. I saw that I can add scopes to the GoogleSignIn object, which I do - <a href="https://www.googleapis.com/auth/user.birthday.read" rel="noreferrer">https://www.googleapis.com/auth/user.birthday.read</a>, <a href="https://www.googleapis.com/auth/userinfo.profile" rel="noreferrer">https://www.googleapis.com/auth/userinfo.profile</a>, but still, I don't see any additional data after the login. Any idea how to get the result of this? Because when these scopes are added to the object, it asks me if I accept to give this data before doing the login, so I guess there should be a way to fetch and display them.</p>
  
  <p>Here is my login code:</p>
  
  <pre><code>  final GoogleSignIn _googleSignIn = GoogleSignIn(scopes: ["email", "https://www.googleapis.com/auth/user.birthday.read", "https://www.googleapis.com/auth/userinfo.profile"]);
    final FirebaseAuth _auth = FirebaseAuth.instance;
  
    Future&lt;FirebaseUser&gt; _handleSignIn() async {
      final GoogleSignInAccount googleUser = await _googleSignIn.signIn();
      final GoogleSignInAuthentication googleAuth = await googleUser.authentication;
  
      final AuthCredential credential = GoogleAuthProvider.getCredential(
        accessToken: googleAuth.accessToken,
        idToken: googleAuth.idToken,
      );
  
      final FirebaseUser user = (await _auth.signInWithCredential(credential)).user;
      return user;
    }
  </code></pre>