Register interest in an order for the purposes of receiving Doshii events when the order is updated. This endpoint is implicitly called for those Apps already associated to the order, for example, if the order is created or updated by the App then they will automatically be subscribed to receive future events related to that order. This is also the case for any Apps making payments against the order.
This is often used by Pay @ Table style Apps that require notifications when an order created elsewhere has been updated so it can be accurately, in real-time, reflected in the App's UI.
For more detailed information on this specific endpoint please review the details found in the OpenAPI docs.