If you ordered your in-ground Pro Dunk system after 9/1/2014 you're good to go.
You can also check your system to see if it has threaded holes at the top of the main pole on the back side. You should see four black plugs ... these are covering threaded holes needed to attach the Backstop Net. If you see these, your system will work easily out-of-the-box with Backstop Net.