问Ajax查询中出现Laravel错误500

EN

function addProductInCart() {
    var product = 1;

    var token  = $('meta[name=_token]').attr('content');
    $.ajaxSetup({ headers: { 'X-CSRF-TOKEN': token }});



    $.ajax({
        type: "POST",
        url: "add_to_cart",

        data: {"product": product, '_token':token},
        success: function (result) {
            console.log(result);
        }
    })
}

Route::post('/add_to_cart', 'AjaxController@addProduct');