Scanned pictures into Photos

You could try to create an special folder in your Pictures folder, where you save the scanned photos. and attach a folder action to this folder that will import all photos to the Photos Library automatically.

This is described in this user tip: Automator Service for an Auto Import Folder

The "Add to Photos" action has not been working reliably, when I last tested it. I am not sure, if it has been fixed by now. test it first on a small, new Photos library.

Or you can scan to a folder (I have an "imports" folder on my desktop) and then in Photos use File->Import to library

Import photos from storage devices and DVDs using Photos on Mac - Apple Support

I created a folder action to import files that were saved to that folder into Photos. It worked fine.

The only caution I would give is to test to make sure it imports successfully before it moves the files to the Trash bin.