core.js：4197错误TypeError：无法读取未定义的属性'TwitterAuthProvider'

Question

   var provider = new firebase.auth.TwitterAuthProvider();
  firebase.auth().signInWithPopup(provider).then(function(result) {
    // This gives you a the Twitter OAuth 1.0 Access Token and Secret.
    // You can use these server side with your app's credentials to access the Twitter API.
    // var token = result.credential.accessToken;
    // var secret = result.credential.secret;
    // The signed-in user info.
    var user = result.user;
    console.log(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;
    // ...
  });

我越来越 core.js：4197错误TypeError：无法读取未定义的属性'TwitterAuthProvider' 运行应用程序时出错