@YuryPol as far as I know, all licenses require some form of documentation. In all cases I know of, this is documented with the license or on the licenses official site.
This module can be used in a standard European wall plate (60mm) to connect to a conventional light switch, blinds, water sensors, motion sensors, etc. at your discretion. Built on ATmega328, 8 MHz clock speed, RS-485 interface. Controls the relay module with RS-485 interface or using Gate 485 - > Ethernet / RF / WiFi