If you ever synced your phone to iTunes on your computer you can try to connect it and back it up to your computer. But this will only work if you had previously established a trust relationship to your computer by syncing it at least once. If you connect it and it doesn’t appear in iTunes (or Filer if you have a Mac with Catalina or Big Sur) then that option is not available.
The only other option: are you sure you didn’t do ANY of these ways of preserving photos?
- emailed, texted or messaged the photos to friends or family
- iCloud photo sync (not the same as iCloud backup)
- iTunes backup
- Transfer your photos to your computer via USB cable
- Apple Photo Stream
- Sync to Google Photos
- Sync to some other photo archiving service such as Shutterfly
- Sync to Dropbox
- Sync to box.com
- Sync to Microsoft OneDrive
- Sync to Amazon Photos
- back up to Livedrive
- Backup to any other backup or archiving service
If the answer is no to all of the above your photos are gone forever.