Type matching DotNet argument

Please see the code below.

.Net expect List<BCLibrary.Contact>, but I am not sure how to specify it in AL. As you see in the error, currently it is System.Object

Any help appreciated. Thanks

bsr.

dotnet
{
assembly(BCLibrary)
{
  type(BCLibrary.BCRouteManager; BCRouteManager) { }
  type(BCLibrary.Contact; Contact) { }
  type(BCLibrary.UploadContactResponse; UploadResponse) { }
}

// assembly(mscorlib)
// {
// type("System.Collections.Generic.List`1"; "List_Of_T") { }
// }
}

codeunit 50100 WrapperCodeunit
{
  procedure UploadContacts(Contacts: Record Customer)
  var
   BCRouteManager: DotNet BCRouteManager;
   Customer: Record Customer;
   ContactL: DotNet Contact;
   ListL: DotNet List_Of_T;
   Response: DotNet UploadResponse;

   begin
    BCRouteManager := BCRouteManager.BCRouteManager();

    CreateContact(0, customer.Name, customer.Address, ContactL);
    ListL.Add(ContactL);

    Response := BCRouteManager.UploadContact('TODO', ListL) //TODO:
    // ListL --> Argument 2: cannot convert from 'DotNet 
    // "System.Collections.Generic.List<System.Object>"' to 'DotNet 
    // "System.Collections.Generic.List<BCLibrary.Contact>"

end;
}