problem with auto_route package after upgrading flutter to 1.22.0

There is a Type to be associated with the builder constructor now.

try this,

import 'auto_route/auto_route.dart';
import 'router.gr.dart' as r;


  return MaterialApp(
   builder: ExtendedNavigator.builder<r.Router>(router: r.Router()),
   ...
  );

I faced issues that Router was defined in multiple files so use an alias while importing if you face such an issue like above.