The key (no pun intended) here is whether you will use a browser key or a server key. Since my PHP script is using file-get-contents($requestURL), where $requestURL might look like this
https://maps.googleapis.com/maps/api/geocode/json?latlng=I will create and copy the server key from the
https://console.developers.google.com/project
Now I am still trying to figure out where to place this code in the PHP/HTML/Javasript page. You'd think that
src="https://maps.googleapis.com/maps/api/js?key=API_KEY">would work. But not necessarily so. Stay tuned.