It doesn’t ‘show’ it in the card as such. The idea is that you use the power value to create a binary_sensor which is either on/off based on the status of the A/C unit. That binary_sensor then reports the A/C on/off state in the card by showing the unit as on/off (or changing the icon colour).
here is an example from one of my devices:
binary_sensor:
- platform: template
sensors:
lounge_gas_heater_power:
friendly_name: "Lounge Gas Heater Power"
device_class: "power"
value_template: "{{ states('sensor.gas_heater_plug_power') | float > 20 }}"
climate:
- platform: smartir
name: Lounge Gas Heater
unique_id: lounge_gas
device_code: 99999
controller_data: remote.lounge_ir_remote
temperature_sensor: sensor.lounge_multisensor_temperature
humidity_sensor: sensor.lounge_multisensor_relative_humidity
power_sensor: binary_sensor.lounge_gas_heater_power