Okay so I am being sued by JP Morgan Chase bank for a business loan I didn't pay because I didn't have the money since I didn't have a job for a while. Anyway the paperwork I received stated that "In order to defend against this lawsuit, you must respond to the Complaint by stating your defense in writing, and serve a copy upon the undersigned attorney for the Plaintiff within 20 daysafter the service of this Summons" What does that mean and how do I make this action?

You answer them by telling them you intend to defend yourself.

So what is your defense ? The amount wrong? You don't owe the debt? Service of court action improper ? Our of the SOL

They want you to state why or what your defense is.