The link doesn't follow the url

[koala-lava]

In this page the first task. Clicking on the link doesn't follow to w3.org. Something is not right.
https://javascript.info/default-browser-action

[masterashu]

This reason for this behavior is the url defined in <a> tag. It refers to http while initial of site is https so most modern browsers will block the request.
On chrome developer console the following error is shown: