imac M1 will not import photos from iPhone 13 pro max

Try using Image Capture to download the photos you want to get into your library to a folder on the Desktop and then try to import from there.

Once they are in the library take a couple of test photos and see if they can be imported via USB cable directly into the library.

Hi

Is your phone syncing with iCloud with optimise phone storage set. If so, any optimised photos (stored only in iCloud) will not be available for transfer via USB.

You should either use iCloud for syncing to your mac, OR USB, but not both.