var provider = new firebase.auth.FacebookAuthProvider();
firebase.auth().signInWithRedirect(provider);
firebase.auth().getRedirectResult().then(function(result) {
if (result.credential) {
// This gives you a Facebook Access Token. You can use it to access the Facebook API.
var token = result.credential.accessToken;
// ...
}
// The signed-in user info.
var user = result.user;
}).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// The email of the user's account used.
var email = error.email;
// The firebase.auth.AuthCredential type that was used.
var credential = error.credential;
// ...
});
But make sure your OAuth redirect URI (e.g. my-app-12345.firebaseapp.com/__/auth/handler) is listed as one of your OAuth redirect URIs in your Facebook app's settings page on the Facebook for Developers site in the Product Settings > Facebook Login config.