How to get values in Razor View ASP NET CORE 6

I working on Invoice Function . I create a seletec box to select the product i want to invoice.Here my razor view

IEnumerable<ProductItem> lstProduct = ViewBag.ListProduct as IEnumerable<ProductItem>

<select class="ddlProduct" name="ddlProduct">
    @foreach (var item in lstProduct)
    {
        <option value="@item.ProductItemsId"> @item.Product.ProductName</option>
    }
</select>
   <select class="ddlSize" name="ddlSize">
       @{
          
           var list = lstSize.Where(n => n.ProductItemsId == selectedProductId);
           foreach (var item in list)
           {
               <option value="@item.ProductItemsId"> @item.Size.SizeName</option>
           }
       }
   </select>
   <select class="ddlColor" name="">
       @foreach (var item in lstColor)
       {
           <option value="@item.ProductItemsId"> @item.Colors.ColorName</option>
       }
   </select> 

The website will be like this enter image description here

I want when a user changes a product, the color and size will also change accordingly the product id of that product. My design database enter image description here

So there is anyway that i can get the productItemsID and pass to Size select box and Color
to get corresponding products

I working on Invoice Function . I create a seletec box to select the product i want to invoice.Here my razor view

IEnumerable<ProductItem> lstProduct = ViewBag.ListProduct as IEnumerable<ProductItem>

<select class="ddlProduct" name="ddlProduct">
    @foreach (var item in lstProduct)
    {
        <option value="@item.ProductItemsId"> @item.Product.ProductName</option>
    }
</select>
   <select class="ddlSize" name="ddlSize">
       @{
          
           var list = lstSize.Where(n => n.ProductItemsId == selectedProductId);
           foreach (var item in list)
           {
               <option value="@item.ProductItemsId"> @item.Size.SizeName</option>
           }
       }
   </select>
   <select class="ddlColor" name="">
       @foreach (var item in lstColor)
       {
           <option value="@item.ProductItemsId"> @item.Colors.ColorName</option>
       }
   </select> 

The website will be like this

I want when a user changes a product, the color and size will also change accordingly the product id of that product. My design database
[2]: https://i.stack.imgur.com/59qTU.png

So there is anyway that i can get the productItemsID and pass to Size select box and Color
to get corresponding products

I have javascript many way but it wont work. Does anyone got solution ? I really appreciate your contribution