I have been running an andriod simulation on intelli jetbrains. However I keep getting this error : "could not find a generator for route routesettings("/", null) in the _widgetsappstate?

void main() {
    runApp(Covid_19_20AppApp());
    }

 class Covid_19_20AppApp extends StatelessWidget {
  get generateRoute => null;

   @override
   Widget build(BuildContext context) {
   return MaterialApp(
   title: 'Covid-19',
    theme: ThemeData(
    primarySwatch: Colors.blue,
  ),
  initialRoute: '/GeneratedAndroid1Widget',
  onGenerateRoute:generateRoute,
  routes: {
 
    '/GeneratedAndroid5Widget': (context) => GeneratedAndroid5Widget(),
    '/GeneratedAndroid13Widget': (context) => GeneratedAndroid13Widget(),
    '/GeneratedAndroid16Widget': (context) => GeneratedAndroid16Widget(),
    '/GeneratedAndroid20Widget': (context) => GeneratedAndroid20Widget(),
    '/GeneratedAndroid23Widget': (context) => GeneratedAndroid23Widget(),
    '/GeneratedAndroid25Widget': (context) => GeneratedAndroid25Widget(),
    '/GeneratedAndroid29Widget': (context) => GeneratedAndroid29Widget(),
    '/GeneratedLowWidget12': (context) => GeneratedLowWidget12(),
    '/GeneratedModerateWidget12': (context) => GeneratedModerateWidget12(),
    '/GeneratedAndroid6Widget': (context) => GeneratedAndroid6Widget(),
    '/GeneratedHoverStateWidget': (context) => GeneratedHoverStateWidget(),
    '/GeneratedPlaceholderTextWidget7': (context) => GeneratedPlaceholderTextWidget7(),
    '/GeneratedListBoxtitleWidget7': (context) => GeneratedListBoxtitleWidget7(),
    '/GeneratedTextWidget': (context) => GeneratedTextWidget(),
    '/GeneratedListboxComponentWidget7': (context) => 
             GeneratedListboxComponentWidget7(),
    '/GeneratedListboxComponentWidget8': (context) => 
             GeneratedListboxComponentWidget8(),
    '/GeneratedListboxComponentWidget9': (context) => 
             GeneratedListboxComponentWidget9(),
    '/GeneratedListboxComponentWidget10': (context) => 
             GeneratedListboxComponentWidget10(),
    '/GeneratedComponent1Widget1': (context) => GeneratedComponent1Widget1(),
    '/GeneratedComponent3Widget1': (context) => GeneratedComponent3Widget1(),
    '/GeneratedComponent8Widget': (context) => GeneratedComponent8Widget(),
    '/GeneratedTextWidget1': (context) => GeneratedTextWidget1(),
    '/GeneratedComponent2Widget': (context) => GeneratedComponent2Widget(),
    '/GeneratedVectorWidget218': (context) => GeneratedVectorWidget218(),
    '/GeneratedVectorWidget219': (context) => GeneratedVectorWidget219(),
    '/GeneratedTextboxuncheckedWidget6': (context) => 
            GeneratedTextboxuncheckedWidget6(),
    '/GeneratedTextboxuncheckedWidget7': (context) => 
             GeneratedTextboxuncheckedWidget7(),
    '/GeneratedTextboxuncheckedWidget8': (context) => 
             GeneratedTextboxuncheckedWidget8(),
    '/GeneratedTextboxuncheckedWidget9': (context) => 
              GeneratedTextboxuncheckedWidget9(),
    '/GeneratedTextboxuncheckedWidget10': (context) => 
                GeneratedTextboxuncheckedWidget10(),
    '/GeneratedTextboxuncheckedWidget11': (context) => 
               GeneratedTextboxuncheckedWidget11(),
    '/GeneratedTextboxuncheckedWidget12': (context) => 
               GeneratedTextboxuncheckedWidget12(),
    '/GeneratedTextboxuncheckedWidget13': (context) => 
                GeneratedTextboxuncheckedWidget13(),
    '/GeneratedTextboxuncheckedWidget14': (context) => 
                GeneratedTextboxuncheckedWidget14(),
    '/GeneratedTextboxuncheckedWidget15': (context) => 
                GeneratedTextboxuncheckedWidget15(),
    '/GeneratedTextboxuncheckedWidget16': (context) => 
               GeneratedTextboxuncheckedWidget16(),
    '/GeneratedTextboxuncheckedWidget17': (context) => 
                GeneratedTextboxuncheckedWidget17(),
    '/GeneratedTextboxuncheckedWidget18': (context) => 
              GeneratedTextboxuncheckedWidget18(),
    '/GeneratedTextboxuncheckedWidget19': (context) => 
              GeneratedTextboxuncheckedWidget19(),
    '/GeneratedTextWidget2': (context) => GeneratedTextWidget2(),
    '/GeneratedTextboxuncheckedWidget20': (context) => 
               GeneratedTextboxuncheckedWidget20(),
    '/GeneratedTextWidget3': (context) => GeneratedTextWidget3(),
    '/GeneratedComponent4Widget1': (context) => GeneratedComponent4Widget1(),
    '/GeneratedComponent7Widget1': (context) => GeneratedComponent7Widget1(),
    '/GeneratedComponent5Widget1': (context) => GeneratedComponent5Widget1(),
    '/GeneratedComponent6Widget3': (context) => GeneratedComponent6Widget3(),
    '/GeneratedEllipse98Widget282': (context) => GeneratedEllipse98Widget282(),
    '/GeneratedCheck_circleWidget': (context) => GeneratedCheck_circleWidget(),
    '/GeneratedCheck_circleWidget1': (context) => GeneratedCheck_circleWidget1(),
    '/GeneratedTEXTBARWidget15': (context) => GeneratedTEXTBARWidget15(),
    '/GeneratedTEXTBARWidget16': (context) => GeneratedTEXTBARWidget16(),
    '/GeneratedTEXTBARWidget17': (context) => GeneratedTEXTBARWidget17(),
    '/GeneratedTEXTBARWidget18': (context) => GeneratedTEXTBARWidget18(),
    '/GeneratedTEXTBARWidget19': (context) => GeneratedTEXTBARWidget19(),
    '/GeneratedTEXTBARWidget20': (context) => GeneratedTEXTBARWidget20(),
    '/GeneratedTEXTBARWidget21': (context) => GeneratedTEXTBARWidget21(),
    '/GeneratedTEXTBARWidget22': (context) => GeneratedTEXTBARWidget22(),
    '/GeneratedTEXTBARWidget23': (context) => GeneratedTEXTBARWidget23(),
    '/GeneratedTEXTBARWidget24': (context) => GeneratedTEXTBARWidget24(),
    '/GeneratedTEXTBARWidget25': (context) => GeneratedTEXTBARWidget25(),
  },
);