i purchased elf 2003 the movie on appletv on my iphone12,how do i transfer it to my mac

If both iPhone and Apple Computer are using the same Apple ID and Password - what was purchased in iPhone should be available on the Apple Computer. Open the iTunes App on Big Sierra and check in Movies section for the purchase.

The downloaded movie should be in your macOS AppleTV library. It will also appear in your Music folder under iTunes media, but is intentionally not in a viewable format there, and must be played through the AppleTV app interface.