I know this post is quite old but I recently encountered the same problem, and after a bit of research, here's what i found

There is'nt any proper cross platform method for this. On android you can add webview but it doesnt work that great.

but here are few other options

1. embedding full webbrowser with cefpython3 (desktop)
2. manually parse the HTML and recreate the UI with Kivy using BeautifulSoup
3. Label + markup for simple html elements (label widget support limited form of markup)
4. Open the HTML in an external web browser (cross platform solution) using python's webbrowser module

I hope this helps someone who's facing the same challenge. It took me a while to figure out the best approach, So i just wanted to share.