Nue Smart Switch HGZB-41 Mystery

I bought this Zigbee light switch many years ago and recently had to disconnect it temporarily. I noticed there was a switch marked SW1 but had lost the instructions years ago. First I tried Googling it but nothing turned up. I tried keywords such as XN-1-3WKG-GBZB-SB T1.1 2019.08.10 which were marked on the circuit board. I also tried HGZB-41 which is marked on the back of the device. I also…