Clicking Properties from the queue manager’s action menu (Selected menu in 11.2) will open the queue manager’s Properties window.
For more information on the properties of queue managers, please go to the IBM Knowledge Center:
https://www.ibm.com/docs/en/ibm-mq/9.2?topic=properties-queue-manager#e_properties_qmanager
See Custom Attributes for information on adding custom attributes to a queue manager (done on the Custom Attributes tab).