First try signing back into iCloud and from: If you're missing photos or videos in the Photos app - Apple Support
Check your Recently Deleted album
Go to Photos > Albums, and tap Recently Deleted in the Utilities section.
On your iPhone or iPad
1. In iOS 16, iPadOS 16.1, or later, use Face ID or Touch ID to unlock your Recently Deleted album.
2. Tap a photo or video, then tap Recover. To recover multiple photos, tap Select, select your photos or videos, then tap Recover.
3. Confirm that you want to recover the photos or videos.
Anything in your Recently Deleted album stays there for 30 days. After 30 days, it's permanently deleted and you can't get it back.