Assuming the you have either paid the TurboTax online account fees with a credit card or have filed the 2018 federal tax return and it has been accepted by the IRS -
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/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the Year and Click on Download/print return (PDF)
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 2018 online tax return.