Home Assistant and Google assistant : how to link HA buttons and Google automation

i am afraid you can’t create a button in hassio.
u can import buttons from integration.
and there is no button domain for google assistant:
Google Assistant - Home Assistant (home-assistant.io)

domains are :

  • alarm_control_panel (arm/disarm)
  • camera (streaming, requires compatible camera)
  • group (on/off)
  • input_boolean (on/off)
  • input_select (option/setting/mode/value)
  • scene (on)
  • script (on)
  • switch (on/off)
  • fan (on/off/speed percentage/preset mode)
  • light (on/off/brightness/rgb color/color temp)
  • lock
  • cover (on/off/set position)
  • media_player (on/off/set volume (via set volume)/source (via set input source)/control playback)
  • climate (temperature setting, hvac_mode)
  • vacuum (dock/start/stop/pause)
  • sensor (temperature setting for temperature sensors and humidity setting for humidity sensors)
  • humidifier (humidity setting/on/off/mode)

biensur tu peu toujour lancer un script , ou un switch qui turn_on/turn_off en 500ms
j’essairai meme un sensor.

template:
  - sensor:
    - name: "CO2 nancras"
      unit_of_measurement: "PPM"
      state: >
        {{ states('sensor.netatmo_maison_nancras_indoor_co2')