I have a gross income tax underpayment invoice from the state of NJ and want to know why, it is from 2021. How do I find out why?

[tpmohan23]

Why is it so difficult to talk with someone from Turbo Tax, since I have paid for the premium version with grantees?

[TomD8]

One common reason for this is that the taxpayer had income that they forgot to include on their tax return.  But no one here would know the specific reason for your situation.  The statement you received normally would explain the reason for the underpayment.  If it did not, then you'll have to contact the NJ Division of Taxation yourself.  The statement should explain how to do that.  No one here can contact them for you.  The State of NJ can't speak to others about your tax return.