Found the error preventing from the Shopping Cart from loading; fixed.

Confirmed that Remove from Cart works.

ShopOnline.Web/Pages/ProductDetails.razor

@@ -24,9 +24,9 @@ else
             </p>
             <div>
                 <button class="btn btn-success"
-                @onclick = "() => AddToCart_Click(new CartItemToAddDto {
+                @onclick = "(() => AddToCart_Click(new CartItemToAddDto {
                     CartId = HardCoded.CartId, ProductId = Product.Id, Quantity = 1, 
-                })"
+                }))"
                 >Add To Cart</button>
                 
             </div>

ShopOnline.Web/Services/ShoppingCartService.cs

@@ -82,9 +82,6 @@ namespace ShopOnline.Web.Services
             }
         }
 
-        Task<List<CartItemDto>> IShoppingCartService.GetItems(int userId)
-        {
-            throw new NotImplementedException();
-        }
+
     }
 }