Manual_mqtt alarm control using mushroom card

Hello Friends, I am new here and my first post to the community. Following https://www.home-assistant.io/integrations/manual_mqtt/#examples I am trying to create a simple chip button to use as custom alarm control button. I wanted to get a number pad on press that can be used to trigger disarm via MQTT.

Here is my code

# alarm_control_panel - MQTT
- platform: manual_mqtt
  name: Home Alarm MQTT
  code: !secret alarm_control_panel_code
  state_topic: home/alarm
  command_topic: home/alarm/set
  pending_time: 30
  delay_time: 20
  trigger_time: 4
  disarmed:
    trigger_time: 0
  armed_home:
    pending_time: 0
    delay_time: 0
  triggered:
    pending_time: 0

The chip card is posting DISARM as state_topic on click, but not opening the number pad. However if clicking on entity under settings, its giving me all options and on click opening the number pad. I am sure something wrong with my understanding or I am missing something. Please advise.

type: custom:mushroom-chips-card
chips:
  - type: entity
    entity: alarm_control_panel.home_alarm_mqtt
    tap_action:
      action: call-service
      service: mqtt.publish
      service_data:
        topic: home/alarm/set
        payload: DISARM

This is what I am trying to achieve and on a valid pass code this should trigger DISARM payload.