Hi Davjoma,
When you need to use hyperlinks in HTML section, you need to click the "</>"(show html) button to add it like below:
<a href="http://www.google.com">Google</a>
Then you can click it again and your text will be like this:

The HTML section support most common Html tags. But the control does not interpret or parse JavaScript code as is not thought download content from Internet
(use the WebView control instead).
For more details, you might refer to App Studio
HtmlBlock sample on GitHub.
Thank you.
Best regards,
Mattew Wu
MSDN Community Support
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