Yes you are self employed and fill out Schedule C. Actually you can just enter it as Other self employment income or as Cash or General income. You don't need to get a 1099NEC or 1099Misc or 1099K. Even if you did you can enter all your income as Cash. Only the total goes to schedule C.
Don't worry about not getting the 1099NEC. As long as you report as much or more income on Sch C line 1 it's ok.
