I don’t have one of these and I can’t find the full specs, but it may technically be a “button,” not a “switch.” Hopefully someone who has one will know for sure. But we can try it as a switch first.
@johnconstantelo may have seen one, he uses a lot of Zigbee.
The good news is there do seem to be some people using them with SmartThings. And all they do is on/off, so a generic DTH/driver should work. I don’t see any indication that people are getting battery level reports.
In any case, first let’s make sure you know how these work.
This fits over an existing dumb switch and doesn’t control that switch at all. So most people leave the dumb switch underneath in the power on position and put smart bulbs in the fixture/lamp controlled by that dumb switch.
When the sage device is pressed, it does one thing and one thing only: send a message to the hub saying “I was pressed.” Seriously, that’s it. It does NOT control the dumb switch underneath. It does not control smart bulbs directly. It just sends the hub a message.
So….you have to create a routine so that if the switch is pressed, the hub gets the message and then the hub tells some other smart device connected to your SmartThings account to do something. Without a routine, nothing will happen.
If the Sage device IS a “switch,” then it will have on and off states, which would be good.
Since you already assigned it to a switch DTH, when you press the switch on the wall does the state change in the app? If yes, you’re all set: just use it in a routine.
If not, you probably need a different DTH. 
