To use Google Maps, you will need to first register your domain name to Google.
You will need to register, then put your domain name (exact url) and then you will obtain a key.
You will need to copy the key and paste it to the website properties in your admin panel.
Example :
if you install the software to http://www.yourdomainname.com/directory, then you must
put the domain name as http://www.yourdomainname.com/directory when you register with google.
Then copy the Google Map API key you got, and paste it in the
Admin panel > Website Setup >Website Properties