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 -
When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state. See screenshot
This will take you back to the 2018 online tax return.
Click on Tax Tools on the left side of the online program screen. Then click on Print Center. Then click on Print, save or preview this year's return. Choose the option Include government and TurboTax worksheets