This needs to be done by the property's IT team on their PMS.
If there is external system, such as AXP, updating rooms or bookings, the location IT team needs to following within Opera for EACH external system:
Go to Administration on Opera
Go to Interfaces
Go to Business Events > External Systems > Add OHIP7157 (Alliants) as publisher of {{external System}}, then add {{external System}} as publisher of OHIP7157 (Alliants)