How to write on macbook screen using apple pencil or trackpad?

Hey everyone,

This is guy is writing on macbook screen, drawing anything, switches back to cursor, then again uses Apple Pencil to draw on screen. I have searched all the internet I could but have not found any way to achieve the same.

Please help me on how do I write and draw on macbook screen like this guy.

Waiting for help.

Thanks in advance.

[Edited by Moderator]