How to fix performance header?

Liked this code codepen.io/hkfoster/pen/zulGs , Copied and tried to run it from spreading on the laptop. but the header does not disappear. Code is not working or I missed something)
July 9th 19 at 10:08
2 answers
July 9th 19 at 10:10
Good afternoon.

Link does not work, at the opening of its 404 (Page Not Found)
codepen.io/hkfoster/pen/zulGs - noel.Schmeler83 commented on July 9th 19 at 10:13
jsbin.com/wopoledevu/edit?htmloutput - vallie_Welch commented on July 9th 19 at 10:16
: what was fixed ?
Code bad? in JS 1 error and 5 warnings - noel.Schmeler83 commented on July 9th 19 at 10:19
Added tags !DOCTYPE, html, head, body - vallie_Welch commented on July 9th 19 at 10:22
July 9th 19 at 10:12
Show that You copied, and how built page.
Copied all the Html, css, js. First, hooked up css, js to the html, using link. Didn't work. I then connected via - noel.Schmeler83 commented on July 9th 19 at 10:15

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