gen2 mqtt control

I've used mqtt explorer to send some commands for gen1 devices

Now when using gen2 devices I can't figure out how that mqtt topic & syntax is going for those devices

topic for devices is shellies/test-pro4pm/rpc

one of json variants what I have used:

{
  "id": 1,
  "method":"Switch.Set",
  "params":{
    "id": 1,
    "on": true
  }
}

Appreciate help to know even one working json syntax

Thank you Seven of Nine I have removed that source each time

Interestingly you can add what ever as source, but it's changes and that misleads me to remove it - now I feel dumb