public async Task <ActionResult <string> > GetBySku(string sku)
        {
            TotalTransactionDTO totalTransaction = null;

            try
            {
                totalTransaction = await _transactionsService.GetTotalTransactionAsync(sku);

                return(JsonConvert.SerializeObject(totalTransaction));
            }
            catch (Exception err)
            {
                _logger?.LogError("Transactions controller exception: " + err.Message);

                return(null);
            }
        }