The action to execute on a specific payment.
ACCEPT
This action can be used to accept PENDING payments.
CANCEL
This action can be used to cancel PENDING payments.
CANCEL_OR_REFUND
This action can be used to cancel PENDING payments.
Or to refund a payment in status ACCEPTED.
We suggest to execute this action only if you don't know the actual status of the payment.
For example if you received a timeout or an HTTP 500.
Depending on the actual status of the payment, you will receive a different outcome and response.