title: undefined is not an object (evaluating 'app.options.databaseURL')
body: <p>For some reason I have been getting this error a lot and i am not sure what's the cause of it. I am creating an app using react native that utilized the same firebase as database for my website as well. For now the goal is to reading data from the firebase and I am not sure if I am declaring or calling any functions wrong since I am still new to this so not sure, what's triggering this error.</p>
  <pre><code>import React from 'react';
  import { 
      View,
      Text,
      TouchableOpacity,
      SafeAreaView
  } from 'react-native';
  import * as firebase from 'firebase'
  import {config} from '../config/FirebaseAuth'
  
  if (!firebase.apps.length) {
      firebase.initializeApp(config);
  }
  
  
  
  class AccountScreen extends React.Component {
  
  
      constructor (props) {   
          super(props); 
          this.state = {
              myItemsReference: null
          }; 
      }
      componentDidMount(){
      
          const myitems = firebase.database().ref(&quot;Item&quot;)
          myitems.on(&quot;value&quot;, datasnap =&gt; {
              console.log('database Worked!!!', datasnap.val());
          });
          this.setState({myItemsReference: myitems});
      }
      componentWillUnmount(){
          if(this.state.myItemsReference) {
              myItemsReference.off(&quot;value&quot;);
          }
      }
  
  
  
      render() {
          return(
              &lt;SafeAreaView&gt;
                  &lt;View&gt;
                      &lt;Text&gt; Hello&lt;/Text&gt; 
                  &lt;/View&gt;
              &lt;/SafeAreaView&gt;
          );
      }
  }
  export default AccountScreen;
  </code></pre>
  <p>the file FirebaseAuth this is what it contains:</p>
  <pre><code>export const firebaseConfig = {
      apiKey: xxxxxx,
      authDomain: xxxxxxx,
      databaseURL: xxxxxx,
      projectId: xxxxxxx,
      storageBucket: xxxxxxxxxx,
      messagingSenderId: xxxxxxxxx,
      appId: xxxxxxxx,
      measurementId: xxxxxx
    };
  </code></pre>