What happens when you use this procedure -
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/
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)
If this is for the 2019 return and the PDF you can download now is incomplete then all you can do is wait until the online system opens for the 2020 tax returns ... at that time the 2019 returns will have been archived and a complete PDF can be downloaded.
You have no choice but to wait if you failed to save a PDF when you could before the 2019 program closed on 10/31. The Online program is estimated to be up sometime this week ... check in once a day until you have success.