Premium themes and the GravityView Maps plugin
If you're using a premium WordPress theme and your map is not displaying on your View, please check your theme settings to see if there is a place to store your Google Maps API key. Several premium themes (Divi, Avada, Enfold, etc.) include a setting for saving your API key in order to use all map related functions with the theme. Examples:
Divi
Settings are located in the "Divi" menu in the sidebar. Click on Theme Options, then the General tab. The API key setting is under "Google API Key".
Avada
The setting is located under the Avada menu. Click on Theme Options, select Contact Form, and then select Google Map.
Enfold
In the sidebar, select Theme Options, then click on Google Services.