make controller

src/Controller/DiffDaysController.php

@@ -21,6 +21,6 @@ class DiffDaysController extends AbstractController
     public function index(DiffDaysRequest $request, DiffDaysAction $action): Response
     {
         $array = $request->serialise();
-        return new JsonResponse($action->act($array[0], $array[1]));
+        return new JsonResponse($action->act($array['startDate'], $array['endDate']));
     }
 }