How to clone form using its URL

I have tried this. After getting access from the original form creator (I was sent the build url) I made adjustments to the form, seeing that I was logged in to my own account. However, what I was doing (but didn't know it) was editing the original form. So, I still don't know how to clone the form.

You can identify the form using its form ID#. All forms uses unique identifier -- form ID#.

So if you actually cloned the form, it should have a different form ID# if you compare to the original form you clone it from.