Accessing photos in Aperture while using Photos

On macOS 13 or newer we can no longer open Aperture Libraries directly in Photos for Mac. But we can import the photos and videos from an Aperture Library into a Photos Library, provided the Aperture Library is an Aperture 3 library (or an iPhoto '11 Library), just like importing items from another Photos Library, see: https://support.apple.com/en-gb/guide/photos/phtcca765b2b/mac

If the Aperture Library is not too large, try the following:

• Restore it with Time Machine to a folder on local volume (as recommended by Yer-Man), preferably in your Pictures folder, if you have enough free storage.
• Create a new, empty Photos Library, if you do not want to import the media from your Aperture Library into your current Photos Library.
• In Photos use the command "File > Import" and select and click your Aperture Library in the file chooser dialog. Click  "Review for Import".
• Wait for Photos to show the photos, that are not yet in your library,  Click Import All New Items or select the photos for import and clickk "Import selected".

Importing directly from the Aperture Library will import the photos stacked as Master-Version pairs, so you can revert them to the original in Photos. But the keyword may be missing, if you have not saved them to the Originals.

Download the free version of PowerPhotos and try to view the Aperture libraries with it. If it can the paid version can merge the Aperture libraries into a current Photos library while preserving most of the organizational effort of the Aperture library and metadata.

A comparison of Photos and PowerPhoto merging capabilities can be found in this user tip; Merging/Importing iPhoto/Photos library into Another Photos Library: PowerPhotos vs Photos.

They appear to be in a Time Machine backup.

The before you do anything you must first restore them from Time Machine