Hi jsanders,
Please check this part, perhaps start at 04:20 [min:sec]
https://www.cineversity.com/vidplaylist/toon_rig_series/toon_rig_series_rig_features
I hope that helps, but since you can do it with the provided rig, that needs a closer look:
I can send you an upload link, so I can take a look at your set up.
Typically one should use the HELP button with the tutorial where the question appears. However, if you had that tutorial, you wouldn’t ask. So I leave it here.
All the best