There is no place on a New Jersey tax return to enter a confirmation number for a federal extension. What makes you think that you need a confirmation number? If you are filing your New Jersey tax return by mail, just enclose a copy of the federal extension (Form 4868).
At the top of page 1 of the New Jersey return there is a box to check if you filed a federal extension. If you filed the federal extension with TurboTax, that box should be checked on the NJ return. If you did not file the federal extension with TurboTax, enter the extension in the federal section of TurboTax in order to get it to check the box on the New Jersey return.
