Schedule SE is part of your personal tax return Form 1040. Any Self-Employment taxes calculated on Schedule SE are entered on Form 1040 Schedule 4 Line 57. The totals from Schedule 4 flow to Form 1040 Line 14.
If your total tax liability is greater than your total tax payments then the amount you owe is entered on Form 1040 Line 22. You pay the federal taxes owed and shown on Line 22 either by check, money order, direct debit from a bank or savings account or by credit card.
If paying by check then the Form 1040-V Payment Voucher is used. The address on where to send the payment and voucher is printed on the voucher.
Or you can pay the taxes owed directly on the IRS website for payments - https://www.irs.gov/payments
In the TurboTax program for tax year 2018 in the File section Step 2 you are given all the options for paying the federal taxes owed.
