Smartthings App won't recognize Smartenit Dual Load Controller (ZigBee)

I am a newbie, so sorry if this is basic, but I spent some time searching and can’t find a fix to this one. I have a Smartthings hub controlling a thermostat and light switch and recently installed a Smartenit Dual Load Controller that I want to use as a remote switch for my hot water heater. However, my Smartthings app won’t recognized the controller on my network as a “thing”. It has no idea how to operate the switch and when I try to add the load controller as a new device, it doesn’t find it. Upon powering down the load controller at the circuit breaker and then powering it back up, it will find my home network and show a solid blue light, then my Smartthings App will recognize it, but only as a “thing” that it can’t control. Has anyone had an issue like this? Any ideas how to remedy this? Thanks. Also, I would have called Smartenit, or Smartthings for that matter, but it’s a three day weekend and I’ll likely have to wait until Tuesday. Thanks in advance for any ideas.

Have you tried the device type in this thread?

No I haven’t, because I don’t know how to do that.

Start here: FAQ - Things That Are Smart Wiki
Look at the following sections:

  1. How do I install a device type/device handler?

  2. How do I install a smartapp?