Sonos volume as a trigger

I have some Sonos speakers outside and am trying to set an alert if the volume goes above a certain amount, to make sure it doesn’t accidentally get turned up and start blasting but I can’t hear it from inside.

I can set the volume_level, but can’t figure out how to use it as a trigger. Wondering if that’s not an option, or if I’m missing something. The volume changes don’t show in the logbook for the device, so maybe it’s not something reported to HA and thus can’t be a trigger? Just hoping to get another set of eyes on this to confirm.

Here is my automation, pretty simple:

alias: Back deck volume alert
description: ""
trigger:
  - platform: numeric_state
    entity_id:
      - media_player.back_deck_2
    attribute: volume_level
    above: 2
condition: []
action:
  - service: notify.mobile_app_pixel_5
    metadata: {}
    data:
      message: Back deck volume high
mode: single

:thinking:

    attribute: volume_level
    above: 0.2

:man_facepalming:

thank you!