Tell me what is the red box and how to get it shown on Google.
Those are Featured snippets.
In your screenshot at the bottom red line you can click on the link that says About Featured snippets which will take you to a Google page which explains them more. That page goes on to say the following:
How can I mark my page as a featured snippet?
You can't. Google systems determine whether a page would make a good featured snippet for a user's search request, and if so, elevates it.