Are you asking about the smartenit 3 toggle switch? There’s an FAQ for that installation it was linked to above (this is a clickable link)
If you’re asking about custom device types in general:
If you’re asking about the LUTRON connected bulb remote, I don’t think there’s a device type for it yet. It just pairs as a thing. After that I believe you can use it with zigbee bulbs that are also connected to your smartthings hub, but there’s no interaction between the remote itself and the hub.
(If you quote a small snippet of whatever you are replying to, it’s easier for everyone to follow the conversation. The discourse forum software is great for a lot of things, but it doesn’t thread replies.)