How can I add html code in the document.

If I write in the document: <p> text </ p> <p >[[++ site_url]] </ p> <p> text </ p>.
That ModX revolution output: <p> text </ p> <p> www.mysite.com </ p> <p> text </ p>
Is it possible to ModX deduced line in the original view?
Sorry for my bad English.

It’s not really MODx that you need to persuade to display your actual HTML code, it’s the visitor’s browser. The way to do that is to replace the HTML code with the corresponding encoding, such as &lt; instead of <

There are some plugins for Evo to do this; personally I have a utility on my desktop that allows me to use various keystrokes to reproduce the encoding as I type, such as option- < will produce the &lt; for me.

If you are referring to the MODx tags, the same thing applies. I believe the code for [ is &#91; and ] is &#93; (not sure, because as I mentioned I have the desktop utility to do it automatically for me).