hi,
how do I split the screen in two
enter formatted text in one half
see its code in another half of the same screen
edit the text or its code in either half and see results in another in real time?

This demonstrates what I want https://html-online.com/editor/

Sorry, I could not find the answer to this very basic question.

Assuming you are talking about the HTML Editor.

In the tool bar, see that little icon with a pencil across a screen? Click on it, and choose the bottom option. You can also just use the key 12. You need to have a page open for the option to become active.

Mind you, you won't be able to edit anything in the preview screen, only in the code half.

Inger, thx a lot.

I will check it soon

you won't be able to edit anything in the preview screen, only in the code half --------- too bad. No other way do edit and see changes in both halves, pls?

No, no other way.