The summons is in New York State for credit card debt
I am looking for what to reply in the answer box for the complaint

I'm in NY. I don't understand what you mean by the answer box.

Is it your debt? Do you have a defense to this action?

"Normally" you would respond with a request that they verify the debt. Have you had correspondence back and forth before this?

There are lots of threads that deal with this situation here.

Generally you respond to the summons with an Intent to Defend. What you say in the letter depends on the circumstances. Usually you say you cannot affirm nor deny this debt until you receive verification of it.

You then send a copy to the plaintiff asking for verification of the debt.