我想使用Crinsane的LaravelShoppingcart,但这个错误让我感到困惑“请提供有效的标识符。”

I tried to integrate Crinsane's "Shopping Cart" but I do not know what I'm wrong with.

structure folders enter image description here or this

"vendor\hardevine\shoppingcart\src\Facades\Cart.php"

This is my cartcontrooler.php

    namespace App\Http\Controllers;

    use Illuminate\Http\Request;
    use App\Product;
    use Gloudemans\Shoppingcart\Facades\Cart;


    class CartController extends Controller
    {
        /**
         * Display a listing of the resource.
         *
         * @return \Illuminate\Http\Response
         */
        public function index()
        {
            $needproduct = Product::needProduct()->get(); //AFISARE 4 PRODUSE INTR-O OARECARE ORDINE

            return view('pages.cart')->with('needproduct', $needproduct);
        }

        /**
         * Show the form for creating a new resource.
         *
         * @return \Illuminate\Http\Response
         */
        public function create()
        {
            //
        }

        /**
         * Store a newly created resource in storage.
         *
         * @param  \Illuminate\Http\Request  $request
         * @return \Illuminate\Http\Response
         */
        public function store(Request $request)
        {
            Cart::add($request->id, $request->name, 1, $request->price)
                ->associate('App\Product');

            return redirect()->route('cart.index')->with('success_message','Produsul a fost adaugat in cos');
        }

And this is Cart from hardevine project

        <?php
        namespace Gloudemans\Shoppingcart\Facades;
        use Illuminate\Support\Facades\Facade;

        class Cart extends Facade {
            /**
             * Get the registered name of the component.
             *
             * @return string
             */
            protected static function getFacadeAccessor()
            {
                return 'cart';
            }
        }
        ?>

this is the error "Please supply a valid identifier." ** if I refresh 2 times my page shows me**