Neo has a zwave one which some community members are using. It’s not really intuitive, because it’s two buttons one above the other and most people will think the top button is on and the bottom button is off rather than that each button toggles a different device. But it does seem to work.
https://www.amazon.com/NEO-Coolcam-Sensitive-Automation-SmartThings/dp/B07F9Z6YK3/
Otherwise, you may be able to use one of the dual micros behind the existing switch.
See the FAQ (the topic title is a clickable link)