Conference Instruction requires a valid post_work_activity_sid
post_work_activity_sid is invalid or no longer exists in the operating Workspace.post_work_activity_sid property in the Worker's attributes or request parameters.1{2"instruction": "conference",3"to": "client:alice",4"from": "bob",5"post_work_activity_sid": "WA0123456789abcdef0123456789abcdef"6}