How to add brand to existing eBay item?

Question

In my application I would like add Brand and MPN to existing eBay item via API on C#, so, I run code:

        string eCommerceID = (dr["eCommerceID"] ?? "").ToString().Trim();
        string upc = (dr["UPC"] ?? "").ToString().Trim();
        string manufacturerName = (dr["ManufacturerName"] ?? "").ToString().Trim();
        string brandMPN = (dr["BrandMPN"] ?? "").ToString().Trim();

        ReviseItemRequestType reviseItemRequestType = new ReviseItemRequestType();
        reviseItemRequestType.Version = version;
        reviseItemRequestType.Item = new ItemType();
        reviseItemRequestType.Item.ItemID = eCommerceID;
        reviseItemRequestType.Item.ProductListingDetails = new ProductListingDetailsType();
        reviseItemRequestType.Item.ProductListingDetails.UPC = upc;

        reviseItemRequestType.Item.ProductListingDetails.BrandMPN = new BrandMPNType();
        reviseItemRequestType.Item.ProductListingDetails.BrandMPN.Brand = manufacturerName;
        reviseItemRequestType.Item.ProductListingDetails.BrandMPN.MPN = brandMPN;

        ReviseItemResponseType reviseItemResponseType = ebayService.ReviseItem(reviseItemRequestType);

but when I execute this code, eBay returns error:

"The item specific Brand is missing. Add Brand to this listing, enter a valid value, and then try again."

What I'm doing wrong?

Appreciate any help. Thanks.

Error:

Answer 1

As the error messages says:

The item specific Brand is missing

Don't use the Item.ProductListingDetails.BrandMPN in your request. Instead you will need to create two Item Specifics called Band and MPN.

<ItemSpecifics>
    <NameValueList>
        <Name>Brand</Name>
        <Value>[BRAND VALUE]</Value>
    </NameValueList>
    <NameValueList>
        <Name>MPN</Name>
       <Value>[MPN VALUE]</Value>
    </NameValueList>
</ItemSpecifics>