Open https://code.google.com/apis/console/. From the drop-down menu select Create.
Use any name that you'd like, click Create Project, select API Access and click on Create an OAuth 2.0 client ID.
Use any product name you'd like and leave the other fields empty, then click Next. On the next page select Web application as the application type. Click more options next to Your site or hostname. Fill in the form with the following values:
Click on Create client ID. Insert Client ID and Client secret in the form below.
Close the help panel and click save changes.