The code view is a text editor setting that lets users edit their content as raw HTML. The code view can be accessed via any text editor on the platform.
Enabling Code View
To turn on code view within any text editor, simply select the three dots in the top right corner and then select the <> button directly below, this is the code view toggle:

Once you have toggled into code view, any preexisting content will now be formated as raw HTML:

You are now free to edit your text however you want. When you're ready to save it's important to note that you MUST re-toggle the code view before saving. If you attempt to save your content with the code view still open, it will not save.