In Viart is selling serial numbers, they are written by hand in the corresponding tab, and after the payment sent to the user by email.
That is: when the user begins to buy the goods, it lays down the basket, choose the method of payment, the payment goes to the page, and not pay(for whatever reason), the serial number is reserved for this customer, and thus removed from sale, order status remains "the new order ", and serial number respectively sent to the user in order cohort with the status of" paid "
What I need: a serial number that is not redundant with the "new order", that is, it turns buying digital products is reserved and immediately sent to the buyer only after successful payment.
