Zaloguj się przez Facebooka w JavaScript ReferenceError: FB nie jest zdefiniowany - javascript, facebook, firebase, firebase-authentication

function toggleSignIn() {
if (!firebase.auth().currentUser) {
console.log("!firebase.auth().currentUser yes");
var provider = new firebase.auth.FacebookAuthProvider();
provider.addScope("user_birthday");
firebase.auth().signInWithPopup(provider).then(function(result) {
console.log("!firebase.auth().currentUser yes");
var token = result.credential.accessToken;
var user = result.user;
document.getElementById("quickstart-oauthtoken").textContent = token;
}).catch(function(error) {
var errorCode = error.code;
var errorMessage = error.message;
var email = error.email;
var credential = error.credential;
if (errorCode === "auth/account-exists-with-different-credential") {
alert("You have already signed up with a different auth provider for that email.");
} else {
console.error(error);
}
});
} else {
firebase.auth().signOut();
}
document.getElementById("quickstart-sign-in").disabled = true;
}