Country database comes with a file that must uploaded to "application/libraries/geolocation/maxmind/db" folder on your site and renamed to "countries.mmdb" so that you end up with this:
Once uploaded, you must set "lookup method" setting to "local database".
Country precision service
This method allows the system to detect user's location by using MaxMind's web service. You must insert your User ID and API key into the appropriate text boxes on the settings page and set "lookup method" setting to "web service". Software caches all requests to minimize your credits usage and enhance performance.
Using both methods
You may use both of the above methods for better accuracy and failover if you prefer. Simply set "lookup method" setting to either "local database + web service" or "web service + local database" depending on the order you would like the system to follow. For example if you set "local database + web service" system will try to look up user's IP address in the local database first, and if not found it will make a request using web service method.