Flutter web app paused at web_entrypoint.dart

I am new to flutter, I was trying to build a web app , and i am trying to save text data to firestore but whenever i run my web app it doesn't run and a new file is opened named web_entrypoint.dart and it hightlights this code This is the highlighted code i have already included firebase script to the html of web app

Here is the screenshot of vscode: vs code screenshot

this is my main function

Future<void> main() async {
  try {
    WidgetsFlutterBinding.ensureInitialized();
    await Firebase.initializeApp();
  } catch (e) {
    print('Failed to initialize');
  }
  runApp(MyApp());
}

Versions - firebase_core: ^1.3.0 cloud_firestore: ^2.3.0 Dart: 2.13.4