title: 'Uncaught TypeError: firebaseApp.firestore is not a function' when integrating Firebase to Vue.js 2
body: <p>I get this error when inspecting &gt;&gt; <strong>Uncaught TypeError: firebaseApp.firestore is not a function</strong>.
  Used dependencies: <strong>&quot;vuefire&quot;: &quot;^3.0.0-alpha.2&quot;,&quot;firebase&quot;: &quot;^9.0.2&quot;</strong>,
  my <strong>db.js</strong> file:</p>
  <pre><code>import * as Firebase from &quot;firebase/app&quot;;
  import 'firebase/firestore';
  import { initializeApp } from &quot;firebase/app&quot;;
  
  const firebaseApp = Firebase.initializeApp({
        apiKey: &quot;x***************************&quot;,
        authDomain: &quot;a**********.firebaseapp.com&quot;,
        projectId: &quot;f****demo-****&quot;,
        storageBucket: &quot;f**********.appspot.com&quot;,
        messagingSenderId: &quot;2***********&quot;,
        appId: &quot;1:**********:web:2**************&quot;
  });
  export const db = initializeApp(firebaseApp.firestore());
  </code></pre>