title: Unable to initialize firebase using JS 9 version
body: <p>I am trying to learn Firebase as I am new to it. I am trying to follow the documentation. However, the console always shows up some error.</p>
  <pre><code>&lt;button type=&quot;button&quot; name=&quot;button&quot; class=&quot;btn btn-danger&quot; onclick=&quot;signIn()&quot;&gt;Login With Google&lt;/button&gt;
  &lt;script src=&quot;js/firebase.js&quot; type=&quot;module&quot;&gt;&lt;/script&gt;
  &lt;script src=&quot;js/custom.js&quot;&gt;&lt;/script&gt;
  </code></pre>
  <p>firebase.js</p>
  <pre><code>// FIREBASE INITIALIZATION
  import { initializeApp } from &quot;https://www.gstatic.com/firebasejs/9.4.0/firebase-app.js&quot;;
  import { GoogleAuthProvider } from &quot;https://www.gstatic.com/firebasejs/9.4.0/firebase-auth.js&quot;;
  var firebaseConfig = {
    apiKey: &quot;XXXXXXXXXXXXXXXX&quot;,
    authDomain: &quot;XXXXXXXXXXXXXXXX&quot;,
    databaseURL: &quot;https://XXXXXXXXXXXXXXXX.firebaseio.com&quot;,
    projectId: &quot;XXXXXXXXXXXXXXXX&quot;,
    storageBucket: &quot;XXXXXXXXXXXXXXXX.appspot.com&quot;,
    messagingSenderId: &quot;XXXXXXXXXXXXXXXX&quot;,
    appId: &quot;XXXXXXXXXXXXXXXX&quot;
  }
  const app = initializeApp(firebaseConfig);
  </code></pre>
  <p>custom.js</p>
  <pre><code>async function signIn(){
    // Sign in using a popup.
    const provider = new GoogleAuthProvider();
    provider.addScope('profile');
    provider.addScope('email');
    const result = await signInWithPopup(auth, provider);
  
    // The signed-in user info.
    const user = result.user;
    // This gives you a Google Access Token.
    const credential = provider.credentialFromResult(auth, result);
    const token = credential.accessToken;
  
  }
  </code></pre>
  <p>When I click on the button this error shows up</p>
  <pre><code>Uncaught (in promise) ReferenceError: GoogleAuthProvider is not defined
  </code></pre>
  <p>Checked my codes again and again but unable to locate error. What should I do now?</p>