I did y 2023 tax refund on turbo tax but did not mail it in. Instead, I filed for an extension. Now I need to change something on the return before filing it; how can I?

[DoninGA]

To access your current or prior 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 2023 online tax return where you can make your changes before filing.