I just bought the following device but cannot figure out how to pair it with ST:
MHCOZY 2CH WiFi RF Wireless Switch Relay,Inching Self-Locking Interlock Mode,Compatible with Alexa Goolge Home (Smart Life app WiFi RF Bluetooth Relay) https://a.co/d/1sOR4uK
It doesn’t connect with smartthings.
What you can do is connect it to the smart life app, set up some tap to run scenes, and then using the smartlife/smartthings integration actuate those scenes from smartthings.
The Tuya app may work better than the Smart Life app.
Tagging @Paul_Oliver
The method in that post will work if the device is one of those that the Tuya/smart life app expose to smartthings through the integration. If so, that’s great.
If it doesn’t, you can still use the tap to run scenes method. So just experiment and see what works best for you. 
The 1st you should do is install the device in the Tuya or Smart Life App.
Then open device tile, click on 3 dots or pencil in upper right corner. One the new page there should be a list of 3rd party integrations. Alexa and Google Assistant will likely be listed and if you are lucky SmartThings (ST) will be listed. I am seeing ST listed on more products lately.
If ST is listed go to add device in ST, select partners and Tuya (not Smart Life) and follow the directions. And you should be good.
If ST is not listed follow my “Tap to Run” instructions that JD posted above. It is a little more involved but is usually very reliable once you set it up
If you have questions feel free to tag me with your questions.
