Alarmo attribute and Custom:Button-Card

I am attempting to make a custom:button-card card that turns red and displays sensor names whenever Alarmo reports an open_sensor. However, I cannot seem to get it to show the attribute value.
Hopefully someone has run into this before and can point me in the right direction. Current card code below:

type: custom:button-card
color_type: card
entity: alarm_control_panel.alarmo
attribute: open_sensors
label: '[[[ return entity.attributes.open_sensors]]]'
show_state: false
show_name: true
show_label: true
name: Open Sensors
styles:
  card:
    - height: 200px;
state:
  - value: null
    color: green
    icon: mdi:door-closed
  - value: Home
    operator: "!="
    color: red
    icon: mdi:door-open
    styles:
      card:
        - animation: blink 2s ease infinite
        - "--keep-background": "true"

Suggest to a post a screenshot for this entity from Dev tools - State to see an internal structure of the entity.

Also, there is no such an option in docs.

Here’s that screenshot. Sorry for the delay