How to get tracked human location in Human Body Tracking with AR Foundation/ AR Kit?

Apple introduced Human Body Tracking in AR Kit last year and AR Foundation brought in the support (thanks!). I wonder how do I get a tracked human body location in a script?

In AR Foundation sample project scene "human body tracking 3D", I tried looking for

 GameObject.Find("Human Body Tracking").transform.position

but I only got the setup location (by default, it's 0,0,0), It does not update when the tracked human move.

I think in the code it instantiate the robot from prefab and I should try to get location of that robot instead, but I don't know how .. Can anyone help?

Thanks