After you file

evidently, the IRS found an error in your return and you owe more taxes than what was covered by your payment.  what we can't tell you is whether or not the IRS is correct. 

you can pay and do nothing further 

or you can hire a pro to check over your return

or you can use the services of 

TaxResources, Inc., also called TaxAudit.com, in partnership with TurboTax. If you paid for Audit Defense and you received an IRS notice, call TaxResources, Inc. at 877-829-9695, or report your IRS notice on their website at http://intuit.taxaudit.com/. Do not contact the IRS until you have spoken to TaxResources. They may contact the IRS on your behalf.