Need automation to check device activity in the past

Configuration
1

I have a dehumidifier installed in my crawlspace under the house. It’s powered via an esphome smart plug. I’m looking for advice for an automation that would send a notification if the dehumidifier hasn’t run for more than 12 hours. The smart plug monitors current so easy to determine if the device is currently running but I don’t know how to create a trigger using the entity history?

Probably would also need to send a notification if the smart plug is not available (power failure).

2

Just have a numeric state trigger of some value below the normal power draw for 12 hours. Could have another trigger for the state going unavailable for whatever specified period of time.

3

How would I set the time?

4

Someting like:

trigger:
  platform: numeric_state
  entity_id: ...
  below: 1
  for:
    hours: 12
5

Perfect​:+1::+1::+1::+1::+1:
Thanks for the help.