terada96,
Understood. If you deleted the contents of your device without a backup, there would not be a way to retrieve that data. However, if you were syncing to iCloud instead of backing up, it's worth signing in to the iCloud website through a browser to see if your photos were synced there: iCloud
If they appear there when you sign in with your Apple ID, try tapping Settings > [name] > iCloud on your device, and make sure that Photos are on to enable syncing.
If the photos were not backed up or synced, there would not be a way to retrieve them otherwise. We hope that helps.
Kind regards.