That FAQ, as the name suggests, is old and crummy :-P
In the latest version drag + drop was no longer the way everything worked (it was confusing to people). What you do is click the action, then click the target (if applicable, not all actions require a target), then right click to confirm. You can also alternatively press space to confirm the action. Finally, you can press escape to cancel an action.
Just as a note, I haven't done anything with this project in about two years. If I hadn't enabled notification for this topic, you might never have gotten a reply. I'm going to leave it so it'll notify me anyway, since some people (like you) will occasionally discover this thing and be interested and then will promptly realize they have no idea how it works, and I don't want to leave them guessing.