Deleted videos

If it is not in the Recently Deleted Album then either you have deleted them 30 days earlier or have never deleted any.

Please check the following

1. iCloud backup doesn’t include information that is synced and stored in iCloud, like Contacts, Calendars, Bookmarks, Mail, Notes, Voice Memos, shared photos, iCloud Photos*, Health data, call history, and files you store in iCloud Drive.
   1. *-If you had turned on iCloud Photos, your content is automatically stored in iCloud. 
2. Probably you may have un-synced photos with Mac / PC, sync them again
   1. For PC: --> Sync photos in iTunes on PC with devices - Apple Support
   2. For Mac --> Sync photos between your Mac and iPhone or iPad - Apple ...
3. Have you ever imported your photos to Mac/PC and used Delete after Import --? Transfer photos and videos from your iPhone, iPad, or iPod ...
4. Have you ever uploaded them to any Cloud Drives Cloud Drives (iCloud Drive, Google Drive, One Drive, Dropbox, Flickr, box, Amazon Drive, Adobe Creative Cloud etc.?)
5. At last but not the least, check the Apple ID that you have signed into your device.

Maybe check on "Recently Deleted" folder, with a little luck they are still there.

Good luck