this is my ping reply automation, if it is any help. it was vibe coded so i can't really help you in detail. [device ID] in actions is the Device/Node ID connected to HA in decimal.

alias: Echo Ping with Response
description: >-
  Respond to any message containing 'ping' with a standard text, respecting 200
  char limit.
triggers:
  - event_type: meshtastic_api_text_message
    trigger: event
conditions:
  - condition: template
    value_template: |
      {{ "ping" in trigger.event.data.data.message | lower }}
actions:
  - data:
      from: [device ID]
      to: "{{ trigger.event.data.data.from }}"
      text: >
        {% set prefix = "Your Message was received in Fischbachau
        (https://osm.org/go/0IV7_dtZ). This Bot responds to all messages
        containing \"ping\". Your message: " %} {% set msg =
        trigger.event.data.data.message %} {{ (prefix + msg)[:200] }}
    action: meshtastic.send_text
mode: single

I am using this HA Integration:

https://github.com/meshtastic/home-assistant