There are two steps to add the Google Map API.
First, how to get it.
1, You need create a goolge account first.
You can use link: www.google.com
2, Link to below web site and log in with your account.
3, You need to create a project first and then create a API Key (Server API Key)，and you need to pay for it.
5, Click the Enable button.
Select the Credentials
Creat a key
And you can get the key
Second, How to add it.
6, Use Note book Open file “gmap.html”
7, To use the following words replace the same line words.