See https://iot-playground.com/ for details
IMPORTANT: use correct firmware version together with EasyIoTESP8266 Arduino library. Use ESP8266 firmware version 0.952. You can download fw on this link: https://iot-playground.com/2-uncategorised/35-esp8266-firmware-flashing If you are usning SW serial, set baudrate to 9600 (default is 115200) with AT+CIOBAUD=9600
See https://iot-playground.com/ for details