Can you tag photos in Apple photos?

In the Photos app on your Mac, select the photos to which you want to add keywords. Click the Info button in the toolbar. In the Info window, click the Add a Keyword field (or the field where other keywords appear if you’ve already added some), then type a keyword and press Return to add it to the photos.

For More Information Please Refer: https://support.apple.com/guide/photos/find-photos-by-keyword-pht8d0ad5198/mac