Setting L-Var value?

[Engin1980]

I am trying ot set PWS switch in A32NX, which, according to the mobilfight (and the plane itself in FS2020) is available as L:Var A32NX_SWITCH_RADAR_PWS_Position.

I have adapted the code, but unfortunately there is no change in the sim when the button is pressed. I have studied #39, but it haven't moved me closer to the solution.

Currently, I have in my .json is like:

...
"index": 10,
"event_press": {
  "type":"condition",
  "event": [ "{{ data_set_simvar_value('A32NX_SWITCH_RADAR_PWS_Position', 1)  }}" ]
}
...

Help from anyone experienced appreciated. TIA