Your channel integration can process a cancellation using the same endpoint used create a new order
As a secondary order in the format below, with the same channelOrderId and "status": 100 (Cancel) this will be recognised by the integrated POS as a cancellation request. The POS will then initiate their own cancellation workflow, which typically involves 'voiding' the order.
Once the cancellation is processed by the POS, a status CANCELED (110) will be returned to confirm this has been handled. See Update Order Status Webhook on how to receive this, and other statuses from the POS.
Cancelling Already Accepted Orders
Once an order has been accepted by the POS, it is often operationally impossible to halt preparation of the order. We therefore advice order cancellations should not be attempted once the status of 'Accepted' (20) or higher has been returned.
NB: There is no validation on our side to prevent cancellation requests based on the order status