Macbook air 2020 beeps every 5 mins

Mac startup beeps: https://support.apple.com/en-us/HT202768

In or out of warranty, you can get a free diagnostics check at the Genius Bar. Have you tried running diagnostics yourself?

https://support.apple.com/en-us/HT202731

This might shed some light on your problem: https://apple.stackexchange.com/questions/361996/mac-makes-beeping-sound-every-five-minutes-without-pop-up-notification-origin-u

Maybe an app you inadvertently reset to beep?

I've seen this before, but the device beeping was a an unrelated device behind the computer.

If not something like that, please supply complete computer specs as found under About This Mac.