Responsive app has not been created yet failure

[cdm2012]

There is an error that is caused during ResponsiveMaterialApp/ResponsiveCupertinoApp creation.

Your responsive app has not been created yet, please move your Responsive Widgets outside of the Responsive app creation.

  @override
  Widget build(BuildContext context) {

    return ResponsiveMaterialApp(
      title: 'Welcome to Flutter',
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Welcome to Flutter'),
        ),
        body: const ResponsiveText('Hello, Flutter'),
      ),
    );
  }