Publish sun state with mqtt

Configuration
,
1

HI
I want to publish the entire state of the sun.sun entity ( not only “below_horizon” or “above_horizon”):

I use this automation:

service: mqtt.publish
data:
  topic: hass/sensor/meteo/sun
  payload_template: '{{ trigger.payload_json }}'

However, this does nothing.

Step Details:

Executed: September 8, 2022, 9:40:27 AM
Result:

params:
  domain: mqtt
  service: publish
  service_data:
    topic: hass/sensor/meteo/sun
    payload_template: ''
  target: {}
running_script: false
limit: 10

What is the correct payload template ?
Thanks