Firebase Auth using Google Sign-in for Web not working

I m just exploring Firebase. I ve set up Firebse Auth using Google sign-in. It just works perfectly in my local while running from my local server. I tried to push it to my github pages, the authentication part failed to work. I ve used signinWithRedirect(), provided the code below. The result of the request is always an object with user:null and it redirects to about:blank. Could someone help me out, thanks in advance.

  var provider = new firebase.auth.GoogleAuthProvider();
  firebase.auth().signInWithRedirect(provider);
  firebase.auth().getRedirectResult().then(function(result) {
    var token = result.credential.accessToken;
    currentUser = result.user;
    console.log(token);
  });