Hello,
I tried to look for device documentation regarding its API:
There seem to be no mentions in API documentation section regadring any Gen3 devices.
A link on the device page itself leads to the Shelly Plus 1PM mini documentation. If to assume this link is correct (the one on the bottom of the page Shelly 1PM Mini Gen3 - All products - Products - Shelly) it might be Gen2 API-wise compatible. If so, you could try a custom driver from this thread for Gen2 device family Shelly Device Handlers for Hubitat - #442 by dmitry.rozovik
