AS ESPHome yaml for home assistant

[PeteAklNZ]

see here in details: https://esphome.io/components/speaker/index.html

So I have this file:
/homeassistant/esphome/kincony-as.yaml
and I've modified the speaker section to:
speaker:
    platform: i2s_audio
    id: va_speaker
    i2s_audio_id: i2s_speaker
    volume: 90%
    dac_type: external
    i2s_dout_pin: GPIO8  #  DIN Pin of the MAX98357A Audio Amplifier
    channel: mono
Then did a quick reload of the YAML, then restarted Home Assistant, but no change in volume.
Is there something else I need to do please?