How can to use the players from the Media Widgets in the body of a post to play audio and video files

While writting this question, I went further to be sure I wasn’t asking something trivial and it seems I was.

I realized the players of both the theme I used and those new WordPress widgets use the same <div class> called .mejs-mediaelement and then I realized it points to MediaElement.js indicated both in the Make WordPress blog post and the first Google result when we search for this name (I thought WordPress had its own workaround, but I was wrong).

However, we don’t need to install the plugin because, as Jacob Peattie explained in a comment below:

WordPress already has MediaElement.js built in and uses it for its
audio and video players.

Then, we just need to add the following shortcodes respectively in order to add audio and video files to our posts:

Then, it’ll look just like the new Media Widgets because they do practically the same, but as a widget, of-course.