How to define width (not embedded) ?

Posted by Ferdesign on Mar 03, 2018; 10:39pm
URL: https://support.nabble.com/How-to-define-width-not-embedded-tp7600172.html

See example:
https://gyazo.com/d011e3628c0a3801b86f309764dfd7ac

My screen resolution is 3440x1440.
Although it looks like the user in the example, hitted an enter (based on the empty spaces between lines) the text continues, without a break up to the next rowline.

I have to downsize the browser (in width) to make it break down to the next lines.

How can I set the width of the page, since its not embedded?
Wider/Narrow are not doing it for me.