Webview html on Widget

[schl3ck]

You can only make a screenshot of the WebView and display that as background image.

More info here:

Scriptable external Webpages

You can render the webpage with WebView and then take somehow a screenshot of them which you then can display in the widget. I saw this tweet and he also has posted the code he used (in the answers to the tweet) so maybe you can replicate it with an external website.