Gmaps API - server domain name


i’m trying to run a google maps api - getting the "Oops! Something went wrong.This page didn’t load Google Maps correctly. See the JavaScript console for technical details."
Should I use the 8080 url or what url should I use? Anyone else have this problem? im using the server.
Accept requests from these HTTP referrers (web sites) (Optional) - Is this optional, i think this is the reason for the error.