Finding position of a link with a fixed joint

Hi,

I’m trying to control a robot using IsaacGym.

Specifically, I would like to add a fixed joint and a fake link, and set the reward based on its position.

However, it seems that only positions of links with revolute/prismatic joints are provided.

Is there any method to obtain the positions of links with fixed joints?

Any help would be appreciated

Sincerely,

Steve