Explanation of the event
The requestCancelExternalPayment event can occur whenever a employee cancels the external payment from the interface.
Part of the External Payment flow
The requestCancelExternalPayment event is an optional step three in a multi-step flow that involves the following events: (1) startExternalPayment, (2) pollExternalPayment, (3) requestCancelExternalPayment and (4) cancelExternalPayment.