I need to know where amount of debt on summons occurred ,I dispute this amount

First its not a good idea to piggyback your question on someone else's. This can lead to confusion. You should start a new thread. So I've moved your question to its own thread.

If you can't find it on the summons, check with the court.

My question is: how can you dispute the amount if you don't know how much it's for?

Or are you saying that you want documentation showing how the debt got so high? Are you being sued by a collection agency or a lawyer? They tend to put high interest and/or fees on the accounts, causing you to owe much more than you originally did.