To create your Google Maps API keys:
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 restreint 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: