Yes. If you have net income from self-employment you pay self-employment taxes. The Self-Employment taxes include both the employer portion and the employee portion of Social Security Taxes and Medicare Taxes.
Self Employment tax (Scheduled SE) is automatically generated if a person has $400 or more of net profit from self-employment. You pay 15.3% SE tax on 92.35% of your Net Profit (If it is greater than $400). The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare (FICA). So you get social security credit for it when you retire.
The SE tax is already included in your tax due or reduced your refund. It is on the 1040 Schedule 2 line 4 which goes to 1040 line 23. The SE tax is in addition to your regular income tax on the net profit.
Are you new to self employment? Do you need to make quarterly estimated payments to cover any SE tax?