Adding TOC anchor links to Markdown/TXT output

I'm converting an ePub book to txt/markdown - then I'm using a markdown converter to output HTML. I'm wondering how to enable links from the table of contents to the heading in the HTML file.

I see that the markdown converter uses the 'toc' extension, and the 'toc' extension allows an option for 'anchorlink' : True. See the extension's usage page for details.

I'd like to know how to enable this for my ePub to markdown conversion. Is it possible without recompiling Calibre?

Thanks,
Jay