To install
You will have to add https://arduino.esp8266.com/stable/package_esp8266com_index.json to your arduino-cli.yaml
arduino-cli config init
vim ~/.arduino15/arduino-cli.yaml
You will have to add https://arduino.esp8266.com/stable/package_esp8266com_index.json to your arduino-cli.yaml
arduino-cli config init
vim ~/.arduino15/arduino-cli.yaml