The ZEN32 is mostly a button device to Hubitat, not a switch. You'll want to chose that type of device in Simple Automation Rules, though Button Controller might be a better app to use for this kind of thing.
The "switch" attribute and on/off commands are only usable on this device for monitoring or controlling the (optional) connected load, which a single tap of the large button does by default. Other buttons (plus really this one too) and multi taps, holds, etc., will get reported as some type of button event, like "button 3 pushed" or "button 1 doubleTapped." Those are what you'd look for as "triggers" in SAR, Button Controller, or whatever app you end up using.