Webhooks are sent for the following cases.
When a booking is made. The event is called
Booking creation
.When a booking is rescheduled. The event is called
Booking reschedule
.When a booking is cancelled. The event is called
Booking cancellation
.
By default webhooks are sent for all the three cases. If you need webhooks for only specific events, you can do that by specifying only the needed events in the "Events" option while creating or updating a webhook.