Why doesn't asp-action work in ASP.NET CORE 2.0?

Question

ASP.NET

view:

@model Product 
<div class="well">
    <form id="@Model.ProductID" asp-controller="Cart" asp-action="AddToCart" method="post">
        <input type="hidden" asp-for="ProductID" />
        <input type="hidden" name="returnUrl" value="@ViewContext.HttpContext.Request.PathAndQuery()" />
        <span class="lead">
            @Model.Description
            <button type="submit" class="btn btn-success btn-srn pull-right"> Add То Cart </button>
        </span>
    </form>
</div>

CartController:

using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using WebEmpty.Infrastructure;
using WebEmpty.Models;
using WebEmpty.Models.ViewModels;
namespace WebEmpty.Controllers
{
    public class CartController : Controller
    {
        List<Product> products;
        public ViewResult Index(string returnUrl)
        {
            return View(new CartIndexViewModel { Cart = GetCart(), ReturnUrl = returnUrl });
        }
        public RedirectToActionResult AddToCart(int productId, string returnUrl)
        {
            products = new List<Product>();
            int col = Operations.Count();
            for (int i = 1; i <= col; i++)
                products.Add(Operations.Read(i));
            Product product = products.ToArray().FirstOrDefault(p => p.ProductID == productId);
            if(product != null)
            {
                Cart cart = GetCart();
                cart.Additem(product, 1);
                SaveCart(cart);
            }
            return RedirectToAction("Index", new { returnUrl });
        }
        Cart GetCart()
        {
            Cart cart = HttpContext.Session.GetJson<Cart>("Cart") ?? new Cart();
            return cart;
        }
        void SaveCart(Cart cart)
        {
            HttpContext.Session.SetJson("Cart", cart);
        }
    }
}

For some reason, the AddToCart() method is not called on button click.
The generated html:

<div class="well">
    <form id="2" action="" method="post">
        <input name="ProductID" id="ProductID" type="hidden" value="2" data-val-required="The ProductID field is required." data-val="true">
        <input name="returnUrl" type="hidden" value="/">
        <span class="lead">
            Protective and fashionable
            <button class="btn btn-success btn-srn pull-right" type="submit"> Add То Cart </button>
            
        </span>
    <input name="__RequestVerificationToken" type="hidden" value="CfDJ8E3bmc_2XN5Fk1av-zNawj1Z6N77o52MbM-UQV5tXxhbdKcSoSFbmsVylQFoAkEBrNDpOWmRRZiL4l4iTpV9QN9-TQt3ufF-GP9aZVLLlUHPkrRRdFCuuAAGsXvvMf_BUFNuBgKUeLW-jSwuK9qP0ws"></form>
</div>

Answer 1

In the view you need to add the line:

@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

Answer 2

I'm dumb, but can you post what you changed with the routing?