i am getting the error message Unresolvable dependency resolving [Parameter #0 [ $app ]] in class IlluminateSupportServiceProvider on the route to the news index function. i ahave set up the API keys and the service providers but still getting the error above

my newscontroller is as follows:

class NewsController extends Controller
{
protected $mediastackService;

public function __construct(MediastackService $mediastackService)
{
    $this->mediastackService = $mediastackService;
}

public function index(Request $request)
{
    $parameters = $request->get();
    $news = $this->mediastackService->getNews($parameters);

    return response()->json($news);
}

}

my mediastackservice.php is as follows:

baseUrl . ‘/news’, array_merge([
‘access_key’ => config(‘services.mediastack.key’),
], $parameters));

if ($response->successful()) {
return $response->json();
}

return null;
}
}

kindly help out