Groove Agent 4 Prerequisites

I just got Cubase Elements, a UR12 audio interface and Groove Agent 4. Everything seems fine for audio tracks. The Halion VST synth also just seems to work. Not so for Groove Agent – no matter what I do, it produces no sound.

What is the trick? Do I need to buy more software and/or hardware to get Groove Agent to produce a sound? I have tried the approaches described in the various Youtube videos – adding an audio track, a group track, etc., various routing schemes… it all seems terribly complicated for such a simple thing. And the Halion VST instrument required none of that – I made a track for it and it just worked. What is the difference?

The platform is Windows 10, but everything else seems to work fine, so I doubt that the laptop is the issue.

TIA, Bill