How do I add schedule c form 1040?

Are you using a version of the software that can prepare Schedule C?   We cannot see what software you are using.   If you are using online, you need Premium.   Or --use any version of the desktop download.

If you have self-employment income for which you will pay self-employment tax for Social Security and Medicare,  you will need to use online Premium software or any version of the desktop software download so that you can prepare a Schedule C for your business expenses.

https://ttlc.intuit.com/questions/2926899-how-does-my-side-job-affect-my-taxes

https://ttlc.intuit.com/turbotax-support/en-us/help-article/form-1099-nec/1099-nec/L5qTsBiSe_US_en_US

https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/26653

https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922

https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax

https://ttlc.intuit.com/questions/1901340-where-do-i-enter-schedule-c

https://ttlc.intuit.com/questions/3398950-what-self-employed-expenses-can-i-deduct

https://blog.turbotax.intuit.com/self-employed/self-employed-tax-deductions-

calculator-2021-2022-50907/

https://ttlc.intuit.com/questions/1901110-do-i-need-to-make-estimated-tax-payments-to-the-irs

If you live in a state with a state income tax, you might need to make estimated payments to your state.

https://turbotax.intuit.com/tax-tools/calculators/self-employed/

https://ttlc.intuit.com/community/business-taxes/discussion/self-employed-don-t-miss-these-tax-moves/00/3400413