Firebase Google Authentication - Check If User Logs In For First Time

I use a Register/Login on my Website which also supports Google Login, the problem is i make a new Data Document in the Firestore with the uid on register, but i cannot do that for

Solution 1:

You can check result.additionalUserInfo.isNewUser to see if the user is signing in the first time. The result returned by signInWithPopup is an UserCredential object: https://firebase.google.com/docs/reference/js/firebase.auth#.UserCredential