Did you efile? Was it Accepted? You either entered your bank account for the IRS to pull it out of your bank account or you send in a check.
How to pay a tax due
You can pay the IRS directly at
Or here is a 1040V voucher slip
VolvoGirl gave you information on how to pay your federal tax. Do you also owe state tax? That has to be paid separately, and it goes to a different place. The details are different for each state.