content: import React from 'react';
  import { render } from 'react-dom';
  import document from 'global/document';
  import firebase from 'firebase';
  
  const config = {
    apiKey: 'REPLACE_WITH_API_KEY',
    authDomain: 'REPLACE_WITH_AUTH_DOMAIN',
    databaseURL: 'REPLACE_WITH_DATABASE_URL',
    storageBucket: 'REPLACE_WITH_STORAGE_BUCKET',
  };
  
  firebase.initializeApp(config);
  const provider = new firebase.auth.FacebookAuthProvider();
  provider.addScope('public_profile');
  provider.addScope('user_friends');
  
  
  const onClick = () => {
    firebase.auth().signInWithPopup(provider)
      .then(result => {
        // This gives you a Facebook Access Token. You can use it to access the Facebook API.
        // const token = result.credential.accessToken;
        // The signed-in user info.
        // const user = result.user;
        console.log('result:', result);
      })
      .catch(error => {
        // Handle Errors here.
        const errorCode = error.code;
        const errorMessage = error.message;
        // The email of the user's account used.
        const email = error.email;
        // The firebase.auth.AuthCredential type that was used.
        const credential = error.credential;
        // ...
        console.error(errorCode, errorMessage, email, credential);
      });
  };
  
  const App = () => <h1 onClick={onClick}>Frontend Only!</h1>;
  
  const div = document.getElementById('app');
  
  render(<App />, div);
  