[BK7231N CB2S] Moes Smart Switch 1 gang WiFi - MS-104

Module name: Moes Smart Switch Module MS-104
Protocol: WiFi 2,4GHz
Input Voltage: 90 - 250V AC 50/60Hz
Max Current: 10A
Wifi module: Tuya CB2S (BK7231N) datasheet

This is the 1 gang vesion of the module there is also a 2 gang version available (obviously with the same PCB based on tear-down).
Bought it on aliexpress from MOES Online store. It has also Zigbee, Zigbee+RF, WiFi+RF versions.
4 gang version has different internals, see tear-down in other topic: Link
Flashed latest release with python flasher: hid_download_py

Pictures of the module:


Tear-down of the module:


Pin config:


Pin23: Button1
Pin24: Relay1
Pin26: Buzzer (works as PWM)

Edit:
One easy way I have found to put CB2S into programming mode to put a solder blob between CSN pad and the cooling pad next to it to ground it: