A post guide how to use BB Code

Hi, I trying to post a topic to guide how to use bbcode markup like this https://markwithtech.com/d/140-how-to-use-the-forum-s-bbcode-markup
But I can do like that post. Please help me how to do it with code (not apply bbcode) and sample
Thanks

Backslash \ before your code.

[code]$this[/code]

#header

*italics*