From the video description:

Alien Resurrection on the Sony PlayStation PS1 has a secret cheat code that has never been discovered - until now. It enables you to play backup discs without any additional mod chip or soft mod. It doesn’t even need a memory card. Let’s take a closer look at what it does and how it works!

This channel is pure solid gold. Love every video he releases.

Here is an alternative Piped link(s):

https://piped.video/uRB7iUCX4KQ

Piped is a privacy-respecting open-source alternative frontend to YouTube.

I’m open-source; check me out at GitHub.