I am trying to recover photos from the iCloud that were saved when I changed to a new iPhone 13

If you had iCloud Photos turned on in the old phone, turn it on in the new one and the photos should automatically sync with it. See: Set up and use iCloud Photos - Apple Support

If you didn't have iCloud Photos turned on in the old phone but do have a backup, use the backup to set up the new phone. See: Transfer data from your previous iOS or iPadOS device to your new iPhone, iPad, or iPod touch - Apple Support