Why did it say you have to print and mail it? Couldn't you find your 2018 AGI to efile?
If you haven't mailed it yet you can try to switch to efile.
Click on Add a State to let you back into your retun.
How to change from Mail to Efile
https://ttlc.intuit.com/community/e-file/help/how-do-i-change-from-mail-to-e-file-in-turbotax-online...
How to mail a return from the Online version
https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online...
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS received the return. Don’t forget state.
Important! Mail Federal and State in separate envelopes and mail each year in separate envelopes.
