title: Flutter Web Firebase TypeError: dart.global.firebase.firestore is not a function
body: <p>I'm trying to use Firebase in my flutter web project.<br />
  But app can't be run with this message.</p>
  <pre><code>TypeError: dart.global.firebase.firestore is not a function
  at Object.firestore$ [as firestore] 
  </code></pre>
  <p>My <code>index.html</code> looks like this.</p>
  <pre class="lang-html prettyprint-override"><code>&lt;script src=&quot;https://www.gstatic.com/firebasejs/7.17.1/firebase-app.js&quot;&gt;&lt;/script&gt;
  &lt;script src=&quot;https://www.gstatic.com/firebasejs/7.17.1/firebase-analytics.js&quot;&gt;&lt;/script&gt;
  
  &lt;script&gt;
    // Your web app's Firebase configuration
    var firebaseConfig = {
      apiKey: &quot;MY_API_KEY&quot;,
      authDomain: &quot;MY_AUTHDOMAIN&quot;,
      databaseURL: &quot;MY_URL&quot;,
      projectId: &quot;MY_ID&quot;,
      storageBucket: &quot;MY_BUCKET&quot;,
      messagingSenderId: &quot;MY_ID&quot;,
      appId: &quot;MY_APPID&quot;,
      measurementId: &quot;MY_ID&quot;
    };
    // Initialize Firebase
    firebase.initializeApp(firebaseConfig);
    firebase.analytics();
  &lt;/script&gt;
  </code></pre>
  <p>Anyone knows how to fix this?</p>