Success URL or Failure URL, depending on the result of the paymentSuccess URL Method or Failure URL Method specified during payment initializationGET request Success URL or Failure URL already contain parameters in query string, then additional parameters pg_order_id, pg_payment_id and custom variables of the merchant are appended to the end of query string. The merchant must ensure that the names of additional parameters do not match the names of existing parametersResult URL and Success URL must be clearly understoodResult URL is called directly from the {{project}} server, while Success URL is called by the user's browser when {{project}} redirects the user back to the store siteSuccess URL as the only way to find out about the completion of the payment, because the user may for various reasons (for example, when the connection is broken) not to reach the Success URL after the paymentResult URL, which {{project}} undertakes to call again every half an hour within 2 hours after the payment, if the first attempt for any reason failed