Prerequisites

Add Firebase to Your iOS Project

You will need to add the Firebase SDK to your iOS project and configure the Firebase Console accordingly. Check out this guide by Google for more information on how this can be done.

Add ‘Sign in with Apple’ to Your iOS Project

You also need to set up your app to be able to use the new ‘Sign in with Apple’ functionality introduced in iOS 13. Here’s a great tutorial on how to configure your app as well as the Apple developer portal.

I highly recommend anyone that does not have an app that fulfills the above prerequisites to pause at the moment and go through the Firebase setup guide and ‘Sign in with Apple’ tutorial. After you have completed all the configurations, you can head back to this article and learn how to perform the integration.

With all that in mind, assuming you have done the configurations, your app should be able to show an Apple authorization form which allows users to sign in with their Apple ID. Furthermore, the Firebase SDK should be properly installed as well.

Apple authorization form

Now is time to get into the interesting part — Integrating ‘Sign in with Apple’ with Firebase Authentication.