Answers for "controller or its method is not found: \app\controllers\kayitol::index"

Class 'App\Http\Controllers\Response' not found

use Illuminate\Support\Facades\Response;
Or
use Response;

Or use full namespace:
return \Response::json(...);

Or just use helper:
return response()->json(...);

Class 'App\Http\Controllers\Response' not found

use Response;
Or use full namespace:

return \Response::json(...);
Or just use helper:

return response()->json(...);