How can I calculate my SEP Ira max contribution amount. Freelance - Net income(income -expenses) is $2779 ?

Once your self-employment income is entered:

1. Open (continue) your return in TurboTax
2. Locate the search bar in the upper right. Search for SEP IRA contributions (use this exact phrase) and select the Jump to link in the search results
3. This will take you to the Self-Employed Retirement Plans screen. Answer No to the question Did you contribute to an Individual or Roth 401(k) plan?
   • If you get the message Self-Employed Retirement Plans are only for self-employed individuals, this means that you haven't entered your self-employed income yet. Once you've entered your income, you can come back to these instructions.
4. On the next screen, answer Yes to Keogh, SEP, and SIMPLE Contributions
5. Continue answering the interview questions until you get to the Your Contributions screen, where you’ll be able to input your SEP IRA contributions.
6. Select Maximize and TurboTax will calculate the maximum amount 

For a self-employed individual, contributions are limited to 25% of your net earnings from self-employment (not including contributions for yourself), up to $58,000 for 2021.

SEP plan limits