It’s been a long time since I found the answer to your question, and I “know” I wrote up a paper for my records but I can’t find it now. I even ordered the correct connectors and I can’t even find those connectors now. Look at page 2 of the Installation Manual where it shows the item #10 which is the “Input and Output Ports”. From an answer from Ortur Tech Support that I/O port does not work with the “toggle Air Assist” function in LightBurn. To use it would require inserting M12-M13 code at the “Start GCode” and at “End of GCode” in the Device Settings that should work to turn those pins ON and OFF each time. This would be to operate a SS relay to activate the air pump. These are the cables I ordered from www.aliexpress.com ( https://tinyurl.com/msxbphsh ) select the 2X3 pin connector to have the 6 pins.
I “finally” found the forum post that tells all about that connector. Thank you Ayrekuebd2000 for sharing the info: Ortur LM3 I/O Port - #2 by aureliend2000