how to return permanently erased iphone

If you did not have backups, and also did not sync your photos to iCloud (these are 2 different processes) then you cannot recover them. You can see if you synced them by logging in to https://icloud.com/photos.

If you didn’t have any backups you will have to set it up as a new phone, and reinstall everything that you had on it. Did you sync any data to iCloud? If you did you can recover that, anyway.

For the future, after setting it up go to Settings/[your Apple ID name]/iCloud and turn on Backup. Then plug the phone in every night and it will back up automatically.

Go through the new phone setup, then restore your most recent backup.