To access your current or prior year online tax returns sign onto the TurboTax website with the userID 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 2019 online tax return.
If you are using the home computer version, you will need to open the original return, add the updated form you want to and then print the pages you want to add. You can also print the entire package again if you want. The print control will allow you to control which page to print, a range of pages or one.