title: Flutter and firebase database connects only when provided with database URL
body: <p>I have been trying to connect to Firebase realtime database and couldn't update/read data. I was using <code>DatabaseReference ref = FirebaseDatabase.instance.ref()</code> to gain reference but apparently couldn't access it. After a while I found out I can use <code>DatabaseReference ref = FirebaseDatabase.instanceFor(app: myApp, databaseURL: myUrl).ref()</code> and it worked. Although I had <code>URL</code> in <code>google_services.json</code>.</p>
  <pre><code>&quot;project_info&quot;: {
      &quot;firebase_url&quot;: &quot;url to my database that is displayed in console&quot;
  }
  </code></pre>
  <p>Why does my app does not recognize Firebase realtime database when not provided with <code>URL</code> on instance? <code>Firestore</code> and <code>FirebaseAuth</code> works just fine.</p>