It appears you’re only working with one of the “SmartThings...” communications library examples.
Try the ST_Anything_Multiples_WiFiNiNa example sketch instead, along with all of the HubDuino Parent and Child Drivers.
This will allow you to create Contact Sensors, Motion Sensors, Switches, Temperature Sensors, Humidity Sensors, Leak Sensors, etc... These will show up just like any other Zigbee or Z-Wave device on your hub, allowing any App to use them.
Once you have HubDuino child devices, then you can use any Hubitat App to interact with those devices.