RAK 4631/19007 External LED Notification

[Hoser01]

I have looked at various pinout diagrams and the spreadsheet tool, but I cannot get an external LED to work for external notifications. Does anyone know the correct pin number to choose in the Meshtastic app to get an external LED (single, not RGB) to work and which pins on the 19007 board? I was trying to use IO1 and ground with a resistor but was unsuccessful.

Thanks,

Hoser