Cannot Add Kinematic Outputs to Deformation Groups

So, I’m a total rigging beginner and am trying to figure out how to create a simple rig with bones in Toon Boom. I’m working on a project that is taking a famous artist’s illustrations and creating a rig within them so that they can be animated. In the scene I’m trying to rig, the main character is being held upsidedown and is swinging back and forth. What I need is to be able to have bones in his body and both arms so that they can move properly and have his arms follow his body as it moves.

Following this tutorial I was able to figure out how to get the arms to follow the rigged body.

However, when I then tried to add bones to the arms everything got messed up. The bones and arm moved to totally different places and wouldn’t work properly. I tried to rig in the opposite order (first the arm, then the body), but I had the same result.

I found this tutorial which mentions kinematic outputs an deformation groups and have been doing my best to follow it, though it seems to be aimed towards people who are’t total beginners like I am.

My best understand of the tutorial is that in order to fix my issue I need to add a kinematic output to my deformation group. Once I do that I can use the kinematic output to link my arms to my body, which should (theoretically) fix my issue. However the tutorial states that the way to do this is through the deformation toolbar. The button is not in the deformation tool bar. I believe that the tutorial was written for an earlier version of toon boom. I cannot find anything similar in toon boom harmony 12.1. Is there a way to do this in the newest version?

To sum up a long post, am I on the right track and if so how do I add a kinematic output to a deformation group?