the guy in this video said in the comments that he wired his proma thc to the MPG port of the controller.
https://youtu.be/Y8vRkYFuBqo
Is it possible that he meant the ModBus interface? Please send me a pinout of that port.
How else could a thc be wired to the controller? You advertised the controller as to be able to control plasma tables.
This one on the video is 4-axis, it doesn’t support MPG, nor ModBUS. It just connected the quick IO
Only these functions can be connected externally

I am not sure how to connect a “torch on” signal via the output ports.
I would like to do that with a relay but how do I tell the controller to send that signal via the connected port? Is that done in the G code?
Could you give me a short example please?

DC+ connects to power, DC- connects to GND, IN connects to OUTFor example, connect to OUT1
Relay module is set to low effective
M201
G04P3000
M101
This code is to close the relay after 3 seconds.
The output of M10x is virtual high, which can be regarded as the internal electronic switch is turned off, and the output of M20x is low, which can be regarded as the internal electronic switch is turned on and the current flows into the ground (GND). X is the OUT port number

It is better to use relay module instead of relay.
The solid state relay is + connected to power supply, – connected to out port