Google Maps not displaying properly

So I get the following error when trying to use Google Maps plugin:

Oops! Something went wrong.
This page didn't load Google Maps correctly. See the JavaScript console for technical details.

I have looked at the Javascript console and it says Google Maps API error: MissingKeyMapError. But I have put in my API key where specified. So I am confused.

Oh and the maps display for a split second and then go to the Oops! message. I have enabled support access. Help!