Can you MOD software on your MacBook Air?

You can change the app settings in most apps but you cannot "MOD" i.e. legally reverse engineer them ( I presume). In addition the built in Apple software is prevented by macOS security from being changed.

"MOD"ding has a very wide connotation. Please describe what you exactly want to do.

Please see https://www.apple.com/legal/sla/docs/macOSVentura.pdf and the section 2. Permitted License Uses and Restrictions.

That's just as vague as the original question.

What are you trying to mod? How are you trying to mod it?

Details matter. We can't read your mind.