Go to https://developers.google.com/maps/documentation/javascript

Then click on on the upper right.

Select the 3 options:

Then select “Create a new project”:

Name your project and click on next.

Create a billing account if you don’t have one (this is mandatory):

The account is automatically restraint to the free trial 300$ limit:

Once you have filled the billing form, hit the “start my free trial button”, enable your API key:

Copy your API key and go to the API console to set the restrictions:

Go to the API restrictions tab:

Select the following APIs:

Save and you’re all set!

Now you just have to copy and paste your API key in your editor in Settings > APIs: 

(this one is used by the app):

and in your backoffice in Settings > APIs

(this one is used by the editor and backoffice functionalities):