Custom ringtone from my macbook air to iphone 14

Launch Finder, then open a new Finder window.

The left side of the Mac screen is for the 1st Finder.

The right side of the Mac screen is for the 2nd Finder.

Make sure the Auto-Lock on the iPhone is set to NEVER.

Connect the iPhone to the macOS.

(from the 1st Finder) Drag and drop a ringtone from Tones folder to (the 2nd Finder) iPhone in iTunes.

If you see a Green Plus sign, drop it.

Have you find where you save that custom ringtone on your macbook air?

If that custom ringtone is not in iTunes Media -> Tones folder, and you don't have a Tones folder in iTunes Media then create a Tones folder.

Go to -> Finder -> your Home folder -> Music -> iTunes -> iTunes Media -> create a Tones folder.

Place the ringtone in that folder.

How do i add a custom ringtone to iphone 14 from macbook air

Where did you save that custom ringtone on your macbook air?

Then it's from that folder.