It’s most likely very similar to the Hue Dimmer Switch. I wrote a device handler for that remote, but unfortunately it doesn’t maintain its connection to ST. Maybe this one will work better.
The linked post has the Github link for that code and I added a lot of comments to the code that explain what I was doing. You’ll want to trigger the configure() method as that’ll be the key to getting it to send messages to ST.
Then you’ll have to use live logging to track what messages it sends for each type of button press and modify the code to react to those instead of the ones I was capturing.