Can I edit my return in Turbotax manually after paying for and printing my return?

You can if you have not e-filed or mailed the tax return.

To access your current year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/

When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state. 

This will take you back to the 2021 online tax return.

Thanks DoninGA. It's good to know that you can go back through the program and make changes to your taxes after printing as long as you haven't filed. TurboTax will recalculate taxes based on the updated entries. However, you can't go in and manually edit calculated results if, for some reason, you disagree with the results.