How can i get back my deleted photos

If you had turned on iCloud Photos and if you delete Photos and Videos from the iCloud it is deleted from iPhone Photos too, and vice-versa. 

Check your Recently Deleted album

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.

If you're missing photos or videos in the Photos app