Click on the "Get Started" button.
Then Select or create a project.
Then set up billing.
In the end, you will get the API KEY.
Important: When you get your Google API Key, by default is not protected, it means, it can be used anywhere.
Make sure you set up the URL where your key will be used.
Go in Google Cloud Platform
Locate the key you have created and enter the url.
Now in src/config/app.js around line 30, add your API KEY