CDN Link in the first Tribute Page Assignment doesn't work

In the first Assignment here:

The CDN testing link given in the end gives a 404 error. Has it moved to another URL. Please also guide me how to test my webpage if I have created it locally on my PC?

If you fork the example project and delete all the html, css, and JavaScript, it already as the following correct cdn link for the test script.

You can use the link above for testing on your pc.