public async Task <IActionResult> CreateAuctionBid(NewBidViewModel model)
        {
            if (!ModelState.IsValid)
            {
                ModelState.AddModelError("", "Niepoprawne dane.");
                return(RedirectToAction("Item", "Item", new { id = model.ItemId, area = "" }));
            }
            NewBidDTO dto      = _mappper.Map <NewBidViewModel, NewBidDTO>(model);
            string    userId   = User.FindFirst(ClaimTypes.NameIdentifier).Value;
            string    username = User.FindFirst(ClaimTypes.Name).Value;

            dto.Username = username;
            await _itemService.AddBidToItemAsync(dto, userId);

            return(RedirectToAction("Index", "Home", new { area = "" }));
        }