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.
_10{_10 "instruction": "conference",_10 "to": "client:alice",_10 "from": "bob",_10 "post_work_activity_sid": "WA0123456789abcdef0123456789abcdef"_10}