I can’t read your code (I rely on text to speech) but if the device is controllable from the official SmartThings mobile app, you should be able to use it with echo just like any other device. However, you do have to individually authorize each device through the mobile app before echo can use it. I can’t read your code (I rely on text to speech) but if the device is controllable from the official SmartThings mobile app, you should be able to use it with echo just like any other device. However, you do have to individually authorize each device through the mobile app before echo can use it. This is true anytime you add a new device, regardless of type.
See step 10 in post one of the echo set up FAQ:
If you do see your devices listed in your Alexa app, they just don’t work, then that’s more likely to be a coding issue and others should be able to help.
Another possibility is that the devices are not of a device class that echo recognizes. It can only provide direct control of switches, bulbs, and thermostats. Again, I can’t read your code, but if it doesn’t show up as capability.switch, echo probably can’t see it.
The usual workaround for that is to create a virtual switch and smart things and have that then control the actual device that you want. That’s how people do things like garage doors. But again, others can look and see what your code is actually doing. 