@Zizzy I do not have this fan controller switch, but I do have around a dozen Tuya/Smart Life devices. They can be integrated with Smartthings, but most of the time you need to use a work around.
1st pair this switch with the Tuya or Smart Life app.
2nd if you open each device in the SmartLife/Tuya app and hit the edit icon (pencil) it will list the “3rd party controls” that are available for that device.
I have a dozen Tuya/SmartLife devices. Most list Alexa and Google controls. Only 1 lists SmartThing.
3rd if you are lucky and Smartthings is listed as a 3rd party control go to add a device in ST and pick Tuya (not SmartLife) and then select other. And run the integration and see what you get.
If Smartthings is not listed as a 3rd party control let me know and I will post the instructions for a work around.