Problem creating mqtt automation

I’m new to HA.
I configured a PI4 with docker and zigbee2mqtt and I’m now struggling to make an automation…

I bought an IKEA stybar…

When I push the on button I see in the log files the following

MQTT publish: topic ‘zigbee2mqtt/ikea->groot’, payload ‘{“action”:“on”,“battery”:100,“linkquality”:167,“update”:{“installed_version”:65572,“latest_version”:581,“state”:“idle”},“update_available”:null}’

I want a light bulb to be on when pushed

What do I have to enter in the automation…

I already have as trigger
platform: mqtt
topic: zigbee2mqtt/ikea->groot
payload: “‘{{ "on" }}’”

type: turn_on
device_id: 2f7031cf05a914b526ff050e6b91201e
entity_id: 10888100a8a8569fdc0d99cef8661831
domain: light

something is wrong with the payload ; )