ESPEasy
From Lolly's Wiki
$ sudo apt install --yes esptool $ wget https://github.com/letscontrolit/ESPEasy/releases/download/mega-20200515/ESPEasy_mega-20200515.zip $ esptool --port /dev/ttyUSB0 --baud 9600 write_flash 0 ESP_Easy_mega_20200516_test_beta_ESP8266_4M1M.bin