Laravel 5.5 Filter on Pivot Array

My Request URL :

http://localhost:8000/api/get-filter-places/z/11,18

No problem query

$kitchen = $request->kitchen;

        $places = Place::where('name', 'like', '%' . $request->name . '%')
            ->whereHas('eatCategories', function($q) use($kitchen){
                $q->whereIn('eat_category_id', [11,18]);
            })->get();

When I write $ kitchen instead of 11,18, it only works as 11.

via Chebli Mohamed