How to write to the GPIO Pins?

Hello everyone, I am fairly new to the LattePanda universe, so please be gentle with me.

I installed Linux Ubuntu 16.04 on my LattePanda Delta 432 to have a Dual boot option with Win10.

Now I am looking for a way to write a "1" or "high" to one of the GPIO Pins via Linux (or Windows?) terminal commands.

Arduino Pins won't work (as far as I know) because the Arduino starts as soon as I press the power button, and not if the system finished booting.

Reason for all of this is, that I want to write a script that is executed automatically upon startup, which will execute these commands, and I do not have internet access on the LattePanda to install any other tools.

So basically, as soon as the LattePanda finished booting, I want a Pin to turn from "Low" to "High".

Thank you all in advance!