How to recover permanently deleted videos from last 30 days?

The recently deleted album is the only safety line offered by Photos. Once the photos are no longer in recently Deleted, you have to use your own backups. What kind of backups are you keeping?

You need a backup you made while the photos have still been on your iPhone, and it has to a backup that includes your photos. The regular iCloud backup of your iPhone will only include photos, if your iPhone is not syncing with iCloud Photos.

See: Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

if you have been using iCloud Photos, and it is not your fault that the photos have been deleted and the photos are very important to you, Apple Support might be able to recover them from Apple's own backups. But you have to hurry - perhaps Apple support will oblige in an emergency.

Otherwise, all you can do now is to learn from mistakes and start making regular backups now, so the next time you will be able to recover your photos.

You cannot. If you deleted them from Recently deleted then you sent them to oblivion.