post
https://app.hosttools.com/api/cancelReservation/
Cancels an internal or direct reservation by its Host Tools reservation ID.
Only reservations with source "internal" or "direct" can be cancelled through
this endpoint. Reservations from external channels (Airbnb, VRBO, Booking.com,
etc.) must be cancelled through their respective platforms.
If the reservation is already cancelled, the endpoint returns success (idempotent).