All groovy device type handlers, including this code, are now obsolete. Smartthings switched over to a completely new platform in 2023, which instead uses edge drivers written in a different programming language.
I haven’t heard of anyone working on an updated version for this, but maybe someone will post if they know.
Here’s the information on the new platform if you’re interested:
FAQ: I have no idea what Edge is. Is that a new developer tool? (2022)