OrderDetails.cs

public async Task Append(dynamic viewModel, RouteData routeData, IQueryCollection query)
{
    var id = (string)routeData.Values["id"];

    var response = await new HttpClient().GetAsync(url);

    dynamic order = await response.Content.AsExpandoAsync();

    viewModel.OrderNumber = order.OrderNumber;
    viewModel.OrderItemsCount = order.ItemsCount;
}