This script can be used to send real time notification via Pusher. To configure pusher, navigate to Left Sidebar -> Pusher Credential Menu. Here is the screenshot of the page:

You need to have an active Pusher Account. You can login into your Pusher Account & create an app to get these credentials. Here is an article to help you with it:

In case you have any query, you can raise a ticket at our support portal.