On June 22, 2016 Google updated Google Maps and how they work on external sites, including within WordPress themes. As part of this change, any instances of Google Maps after this date require a unique API key to work correctly. You can read more about this change here.
Envato Studio’s Express WordPress Installation service does not include the setup of Google Maps, however your service provider may be able to assist with this for an additional fee.
For information on connecting your theme with Google Maps, we recommend contacting your theme’s author via their dedicated support page on ThemeForest.