How to show if currently heating/cooling in the climate card and KNX integration

I have configured the KNX thermostats to run in HA for my underfloor heating, and it works like a charm. Now, I would like to show if a room is being currently heating or not.

I have configured the active_state_address to get the status of the room electrovalve. It seems that active_state_address changes the climate attribute hvac_action. My plan was to use this attribute in the climate card.
The thing is that I cannot find the hvac_action as feature in the developer tools.
What I am missing?

This small icon indicating the action is what I would like to get when the EV is open:

image

    - name: "MyRoom"
      temperature_address: 3/3/222
      target_temperature_address: 3/2/220
      target_temperature_state_address: 3/3/220
      operation_mode_address: 3/2/221
      operation_mode_state_address: 3/3/221
      active_state_address: 3/4/220 
      operation_modes:
        - economy
        - comfort
        - standby