ETRX357 Zigbee Module Integration

That’s using the “Zigbee pro” profile, not the “zigbee home automation (ZHA)” profile which smartthings uses. It may or may not work depending on the exact clusters you are using. But it should join, so you can see how far you can get. ( I don’t know if that particular device allows you to use the ZHA stack or not)

As far as writing a device type handler, you will need to be using the classic app. Then see the following intro FAQ: