Need help about contenteditable.

Question

https://code.sololearn.com/WtHMs4O8MBeS/?ref=app

Add some text in the edit area, and click "format".
Then all of the text I entered will be collapse in one line.
How can I fix it?

(Sorry for my bad English.)

Answer 1

1- https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Editable_content
2- https://www.w3schools.com/tags/att_global_contenteditable.asp