After struggling for two days, I finally succeeded in flying a Tello toy drone automatically.
I often use the toy drone priced at around 5,000 yen. It's good for practice because it's safe to fly indoors, and it's less stable than the bigger one (like a Phantom one) so I can improve its flight stability by using it.
Recently, I bought a Ryze Tech Tello toy drone, which is expensive for a toy drone. Because I found out that the Tello could be flown automatically from a book.
At first, I installed the latest version of Scratch without reading the book carefully. And I became confused because the action of the application was different from the description in the book. I solved this problem by installing the old version "Scratch 2.0 Offline Editor" again.
The book is written for Windows, which made me even more confused because I usually use Mac. One of the different parts is to run a node.js but it's explained in Sky DRONE's video "Programming RYZE Tello with Scratch (Mac edition)" and, which was helpful for me.
Unlike manual operation, there are restrictions such as not being able to do more than two operations at the same time, but it seems to be possible to do some interesting demos.