Will generate a Payment object and return it as a successful response.
Optional amount argument can be included in the request body to request a partial refund.
Consult refund_availability field on Purchase on details whether this Purchase can be refunded or not.
If this operation takes too long to be processed on the acquirer side - you will get a response with status code 200 and a Purchase object having status = pending_refund in body (you will receive a corresponding Webhook callback too for a purchase.pending_refund event). To be notified of a successful operation completion, please subscribe to payment.refunded callback event - it will deliver a Payment generated by this refund.
If refund fails due to payment processing error, you will receive HTTP response code 400 with error code purchase_refund_error. In this case, to get more details about the error, you should perform a GET /purchase/ request for the Purchase you tried to refund. In transaction_data.attempts[] array (newest element first) you'll find the corresponding attempt with error code and description in .error parameter.