1. At the TinyMCE editor, click [Insert/Edit code sample] button to insert code.
2. Select the language you want to code.
3. Type in your code.
4. click [OK] to close the code editor.
5. The result is as below.
6. If you want to add line numbers, click at the lower-right of TinyMCE to view the source HTML code of the article.
7. In the class block, add line-numbers, like the example below.
<pre class="line-numbers language-markup">
8. The result is as below.