iCloud photo's

Are your photos still in the Recently Deleted album?

See: If you're missing photos or videos in the Photos app - Apple Support

If your photos have already been deleted from Recently Deleted, you can only recover them from a backup you made, before the photos got deleted. What kind of backup are you keeping of your iCloud documents and data?

Recently Deleted is the only safety line iCloud offers for photos. But the album is automatically emptied after 30 days. We have to recover the photos within the 30 days. And if we are low on cloud storage, photos will be deleted immediately. We need local backups of our cloud data as well, so we can recover accidentally deleted items.

Have a look at his recommendation: Archive or make copies of the information you store in iCloud - Apple Support