To get an API key:
- Visit the Google Cloud Platform Console.
- Click the project drop-down and select or create the project for which you want to add an API key.
- Click the menu button and select APIs & Services > Credentials.
- On the Credentials page, click Create credentials > API key.
The API key created dialog displays your newly created API key.
- Click Close.
The new API key is listed on the Credentials page under API keys.
(Remember to restrict the API key before using it in production.)
At last insert your API Key in Options (Customizer) > API > Google map, and you are done!