Here’s an old but useful blog article on adding a USB stick to smartthings. Everything is pretty much the same except you won’t have to select. “add generic zwave device“ anymore, just scanning for a nearby device should be enough.
Also, note that all of the fancy screens you see in the article are not part of smartthings: they are the software that the author recommends for use with the stick. Yours may look a little different because you have a different brand of USB stick, but all the basic concepts are the same.