Need help writiing a value template for automation

Configuration
1

I will start out by saying that I am a noob here. I need assistance writing a value template for a sensor called sensor.carpresensesignal. I want an automation to trigger when the numeric_state of the sensor stays the same or does not change for 20 seconds but cannot find any documentation on “stays the same” for numeric_state values. Any help would be greatly appreciated.

2

I think that the Example in the Automation Documentation will work for you!
The value_template: depends if the value of your sensor is the state or an attribute
Numeric state trigger

  automation:
      trigger:
        platform: numeric_state
        entity_id: sensor.carpresensesignal
        # Optional if the value is an attribute
        value_template: '{{ state.attributes.battery }}'
        # At least one of the following required
        above: 17
        below: 25

        # If given, will trigger when condition has been for X time.
        for:
          hours: 0
          minutes: 0
          seconds: 20