How to make a good Study?

How can I make a study that hides the answer, and there's a explanation with a blue-octopus?
Can someone tell me? (also, you can teach me)

A example how I want to do it: lichess.org/study/Gw27u6Wl
(Credits to RoyalTopChessClub)

You can choose to do this in a chapter-by-chapter basis. It's called "Interactive lesson." In my study, some chapters were normal analysis (like chapter 2), and some were interactive lessons (like chapter 5):



When you create a chapter, click analysis mode -> Interactive lesson. From there, you make the moves for the main line and comment/give hints/etc for all the other moves that "fail." Keep in mind that the study will look different on your screen than any random viewer's screen, so don't get confused. Good luck!

Thank you very much! :D