Configure your smart switch module to work with Tasmota open source firmware.
Shelly 3EM Power Monitoring Module Sensor (SHELLY3EM) Configuration for Tasmota
NOUS - Tasmota WIFI connected module ON/OFF 10A 1 channel
Shelly EM not reporting data · Issue #14261 · arendst/Tasmota · GitHub
New Device Procedure
Temperature Alarms: Using openHAB 3, Tasmota, & Shelly 1, by Rob Clark
Shelly 2.5: Flash ESPHome Over The Air!
Controlling multiple devices with the Sonoff NSPanel and Tasmota - James Ridgway
Support for Shelly EM · Issue #8055 · arendst/Tasmota · GitHub
Support for Shelly 3EM · arendst Tasmota · Discussion #13515 · GitHub
Shelly Plus 1PM Mini Review: Size Does Matter - SmartHomeScene