HTML element map not working on preview

Hi! I’m trying to do something really simple with an HTML element but I can’t get it to work. All I want to do is to display a map from HERE Technologies. I have achieved this when running the same code using Visual Studio Code.

I have an HTML element with my code in it and when I’m in editor mode, the map does show, but once I get into preview, I can’t see anything.

Thanks!