Create a Google Maps API Key

All new websites created after June 22, 2016 are required by Google to use an API key to access the Google Maps API services. 

It is recommended for all sites regardless of creation date to add a Google Maps API key.

To generate your API key, you need to   access the Google Developer console. In the Google Developers Console, follow these steps:

Create Project

Generate API Key

On this screen chose the "HTPP Referres" 

It's important to add your website URL to " Accept requests from these HTTP referrers" field, make sure to add it as

*.yourpage.com/*

this way all subdomains and subpages will be accepted. It sometimes takes couple minutes to have your site accepted. After adding it, click Create.

If you have any problems with using API, you might want to try the option "None" - your API key won't be restricted to your website

Copy API Key 

and paste it in your WordPress dashboard -> Settings -> TravellerPress

Enable APIs

Go to LIbrary -> Google APIs and click  Google Maps JavaScript API -  Enable the service.

APIs you need to enable to get full functionality of WPVoyager are marked on this screenshot