UI-Extension not working in standalone javascript file!!!

I been following the UI Extension tutorial in Contentful and ran into an issue using npm start. When I start the server nothing displays to the browser. Even trying to log to the console in the javascript file nothing shows, but it tends to work when I place the code in the Index.html script tags.

Can someone explain what I am doing wrong?

Hi @mjubilee,

Could you explain in more detail what you tried to do here, including the specific commands and snippets of code used? (omitting sensitive information, of course)