title: No Firebase App has been created - call Firebase.initializeApp
body: <p>[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()</p>
  <p>I kinda understand the error but whereever I put it, it doesn't work...
  I am trying to return only a string and a number value from firebase. And I also did all the requirements. build.graddle in android folder, and build.gradle in android/app folder. Everything. In addition to that I also did:
  cloud_firestore:</p>
  <p>to the dependencies on the pubspec.yaml. Now my main.dart looks like this, but gives so much errors I can't paste here. It's very long. I was using this video as a base but it doesn't work..</p>
  <pre><code>import 'package:flutter/material.dart';
  import 'package:cloud_firestore/cloud_firestore.dart';
  
  void main() {
    runApp(MyApp());
  }
  
  class MyApp extends StatelessWidget {
    // This widget is the root of your application.
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
          visualDensity: VisualDensity.adaptivePlatformDensity,
        ),
        home: MyHomePage(title: 'Flutter Demo Home Page'),
      );
    }
  }
  class MyHomePage extends StatefulWidget {
    MyHomePage({Key key, this.title}) : super(key: key);
    final String title;
    @override
    _MyHomePageState createState() =&gt; _MyHomePageState();
  }
  class _MyHomePageState extends State&lt;MyHomePage&gt; {
    int _counter = 0;
    void _incrementCounter() {
      setState(() {
        _counter++;
      });
    }
  
    Widget _buildListItem(BuildContext context, DocumentSnapshot document) {
      return ListTile(
        title: Row(
          children: [
            Expanded(
              child: Text(
                document.data()['adSoyad'],
              ),
            ),
            Container(
              decoration: const BoxDecoration(
                color: Color(0xffddddff),
              ),
              padding: const EdgeInsets.all(10.0),
              child: Text(
                document.data()['yas'].toString(),
                style: Theme.of(context).textTheme.headline4,
              ),
            ),
          ],
        ),
        onTap: () {
          print(&quot;bisey&quot;);
        },
      );
    }
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: StreamBuilder(
            stream: FirebaseFirestore.instance.collection('tablolar').snapshots(),
            builder: (context, snapshot) {
              if (!snapshot.hasData) return const Text('Loading...');
              return ListView.builder(
                itemExtent: 80.0,
                itemCount: snapshot.data.documents.length,
                itemBuilder: (context, index) =&gt;
                    _buildListItem(context, snapshot.data.documents[index]),
              );
            }),
      );
    }
  }
  </code></pre>