Please add support for Develco Smart Relay

I really would like to see support for the Develco Smart Relay, as seen here:

and here:

But I cannot figure out how to do it myself.
I use Homeassistant with a NUC and, and can’t really figure out the guide on how to add new devices.
Should I use external_converters and devices.js or should I use `zigbee-herdsman-converters?

There are no fromZigbee.js file or devices.js file in
I’m confused.

That’s why I ask if someone else please would do the task.