How to get the id from detected object in deepstream?

Hello guys, i want to ask you here, can i get the unique-id from detected object in deepstream ? because when i try the code from,, and None of them resulting the unique id from detected object.

At first, i was expect that this line of code is for get the unique-id, but in the result when i print this, the result is “-1”
msg_meta.trackingId = long_to_int(obj_meta.object_id),, and do not have tracked added, have tracker, you can use it for getting tracking id.

Thank you amycao