Mine has an “Air” option on each layer. If I enable this the air is on for that layer. My air supply is connected to the machine for power so it can cycle it on and off. Is your pump connected to the machine or is it completely separate?
Here’s a screenshot of the option.
I don’t connect my computer to my laser. Instead, I transfer via G-Code files on USB or SD. There are lots of limitations to doing it that way and this would be a lot easier with a computer connected to the laser.