Change display name for firebase google auth provider

Question

I am trying to display the name of my website on AuthO popups. No issues with Facebook, Twitter or GitHub auth. But Google's popup keep showing 'Sign in to continue to projectName.firebase.com' Instead of 'example.com'. I mean it shows firebase's default domain instead of custom one.

Even if I change display name to some custom name in console.developers.google.com.

Answer 1

In the newest version of Firebase user guide they explain how to fix this, by pointing authDomain initialization property to your domain, and making a few other preparations: https://firebase.google.com/docs/auth/web/google-signin#customizing-the-redirect-domain-for-google-sign-in

1. Create a CNAME record for your custom domain that points to your project's subdomain on firebaseapp.com:
   auth.custom.domain.com CNAME my-app-12345.firebaseapp.com
2. Add your custom domain to the list of authorized domains in the Firebase console: auth.custom.domain.com.
3. In the Google developer console or OAuth setup page, whitelist the URL of the redirect page, which will be accessible on your custom domain: https://auth.custom.domain.com/__/auth/handler.
4. When you initialize the JavaScript library, specify your custom domain with the authDomain field

Update: one important detail that's missing from the instructions is that the custom auth domain must be configured for Firebase Hosting (i.e. add it to the list of custom domains for Hosting on the Firebase Console). Otherwise you will get a certificate mismatch error as @AmritanshSinghal correctly points out.