Trigger binary Input on Shelly Uni with MQTT

Hi all,

Im currently struggeling with the Shelly Uni binary Inputs connected via mqtt to HA.
HA delvers the following Events when I connect VCC to the binary inputs:

image

But how can I use this event in anutomation?
This code is not working?

alias: UI_ShellyUni_Türklingel
description: ""
trigger:
  - platform: mqtt
    topic: shellies/shellyuni-34945478FD4E/input_event/1
    payload: S
condition: []
action: []
mode: single

anyone an idea how to sove this?

Hi all,

is there noone who has an idea to trigger on the event= “S”?