You can use the Shorten application UI to shorten your link or by making a GET or a POST request to the app as shown below.

From your address bar - In case you are in a hurry, you can go to http://nusacm.org/apps/shorten?url=original-url to quickly shorten your link.

From your code - You can also make a POST request to http://nusacm.org/apps/shorten with a single parameter url and get back a JSON response which has the shortened URL.