WIFI/Network status LED

Uuuupsss… So maybe any “free” output port that can be operated via a script? I’m asking because I’m currently polishing my first Volumio device, and my idea was to add some LED indicators to show simple things like power or RPi activity. These were simple to set up, but then I tried to add a “WiFi on” LED and got stuck here. I have no idea how to control GPIO output via a script in Volumio.