Crypto deposits are similar to bank transfers. If the recipient’s bank account number is known then the funds can be directly sent at any time. This approach differs from classic payment methods because the transaction cannot be created before the funds have appeared in the bank account. The same way web-services cannot expect that crypto deposit transactions will be initiated from the "payment form" every time because, in general, there is no such term for cryptocurrencies. Unlike the classical approach, web-services should handle callbacks from payment providers with information about received deposits. When web-services receive the first callback they then create the transaction. After the transaction will be confirmed by the payment provider the second callback will inform the web-services about the status of the transaction. Then, web-services can provide the user with a specific service.