public async Task <IActionResult> Delete(int id)
        {
            if (ModelState.IsValid)
            {
                var bill = _repository.GetBillsByUser(new Guid(_userManager.GetUserId(HttpContext.User))).FirstOrDefault(b => b.Id == id);
                if (bill == null)
                {
                    return(BadRequest("You cannot delete another users bill."));
                }
                _repository.DeleteBill(bill);

                if (await _repository.SaveChangesAsync())
                {
                    return(Ok($"api/bills/"));
                }
            }
            return(BadRequest("Failed to delete the bill."));
        }