Listorders = _orderService.SearchOrders("", "", "", 0, null, DateTime.MinValue, DateTime.MaxValue, 0, 100, 0);
OrderModel order = _orderService.GetOrderById(orderId);
OrderModel order = _orderService.GetOrderById(orderId); order.OrderStatus = OrderStatus.Complete; _orderService.UpdateOrder(order);The Nop.Admin.Models.Orders OrderModel is part of the Nop.Core.Admin assembly found in the NopCommerce package.