Your self-employment taxes are included in your total tax and if you get a refund it was subtracted from your withholdings already. If you have a balance due, it was added into you tax liability. You do not have to do anything other than file your income tax return.
Your self-employment income is reported on Schedule C of your Form 1040 and your self-employment tax is calculated on Schedule SE (if your self-employment income minus expenses is at least $400). That amount shows up as Other Taxes on Schedule 2 line 4.
Please review TurboTax article The Self-Employment Tax for more information.