How come I am not able to clone the jotform as stated in the link?

The custom URL does not work the same way as the regular URL for the form.  Try cloning the form using this URL instead:

http://www.jotform.me/form/71408657983469

Thanks for the reply David! May i ask how am i able to get the original / unedited URL of any jotfrom? Thanks!

View the form source. In Google Chrome, right-click on the page and click View Page Source:

In the page source page, find (CTRL + F) "formID". Its value is the form ID and you just need to construct its URL.

In the image above, the ID is 71408657983469. Just do it like https://www.jotform.com/71408657983469. 

I hope that helps.