If you deleted a video years ago, it is unlikely to still be in your phone's physical memory. However, it may still exist in a cloud service you once used.
Be wary of apps that ask for payment before showing you the recovered file, or apps that require root access just to scan. If an app promises to recover data from a factory-reset phone without a backup, it is scientifically impossible—this is a scam. If you deleted a video years ago, it