Adding battery sensor information on top of a mushroom lock card

Configuration Frontend
1

Hi, trying to add lock battery information to a mushroom lock card, have tried card-mod to no avail, would appreciate any help with this, this is the basic configuration I got so far:

type: custom:mushroom-lock-card
entity: lock.entrance_door
secondary_info: last-changed
double_tap_action:
  action: more-info
hold_action:
  action: url
  url_path: http://192.168.1.167
2

Ended up with this solution which is sufficient for my needs:

type: custom:mushroom-lock-card
entity: lock.entrance_door
secondary_info: last-changed
double_tap_action:
  action: more-info
hold_action:
  action: url
  url_path: http://192.168.1.167
card_mod:
  style: |
    ha-state-icon {
      {% set battery = states('sensor.entrance_door_battery_level') | int %}
      {% if battery <= 20 %}
        color: yellow;
        animation: blink 1s infinite;
      {% elif battery <= 10 %}
        color: red;
        animation: blink 1s infinite;

      {% else %}
        animation: none;
      {% endif %}
    }

    @keyframes blink {
      0%, 100% { opacity: 1; }
      50% { opacity: 0.2; }
    }

Used some ideas from this great community post