PRIVACY.md
The Markdown Here browser extension strictly does one thing: Allows users to convert Markdown to HTML inside a rich edit control. Not one thing else.
This means that:
If you choose to use Markdown Here's LaTeX math rendering feature, the contents of your math equations will be sent to a third party to create the image containing your math. (That image is created at the time that the browser displays it, which is usually when the image element is inserted into the page). By default that third-party service is CodeCodgs although other services may be used.