I guess the dropdown you are talking about, is the one you use to check if you’ve passed the test/requirements?
I’m having the same trouble. I’ve done these tests a year ago, and everything was functioning as described. You forked a page from Codepen, and inside this page you would find a dropdown to choose from.
Now something seems to be missing. I tried in both Chrome and Safari, and I even tried some of my old Codepens, but no dropdowns showed up.