Why firebase phone auth requires a custom URL scheme to be registered in Xcode?
问题 If my understanding is right, custom URL schemes are registered to launch the app using a different url. For example: if custom scheme foo is registered, then the app can be launched using foo://<params> url. If that is the case, why firebase phone auth requires registering a custom URL scheme? 回答1: Firebase Auth for iOS requires a custom scheme in case an APNs token is not available for whatever reason. This is needed since phone auth in iOS relies on push notifications for security purposes