For 2018,
Try printing from the Print Center
Log back in your TurboTax account and "add a state" to open the return back up (you are not really adding a state, just to open it back up), then
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
How to save the PDF
https://ttlc.intuit.com/community/saving/help/how-do-i-save-my-turbotax-online-return-as-a-pdf/00/26...
For 2017 what version did you use? When does access to prior years expire?
https://ttlc.intuit.com/community/prior-year-return/help/when-does-access-to-my-prior-year-turbotax-...