A 2019 return cannot be prepared using online software. Online software and e-filing for 2019 has been closed since October 2020.
Online tax preparation and e-filing for 2019 returns is now permanently closed. You had until midnight on Thursday, October 15, 2020 to finish and attempt to e-file; if your e-file was rejected you had until October 31, 2020 to make corrections and re-file. Now it is too late to use online software or to e-file. If you have any changes/corrections at all to make to your 2019 return, you now have to complete it using desktop software, which you must download to a full PC or Mac (not to a mobile device).Then you need to print, sign and mail it.
If you already paid for your online software you can ask customer support for a download of the desktop software.
They are available from 5 a.m. to 9 p.m. Pacific time Monday-Friday.
If you are getting a refund, there is no penalty for filing late. If you owe tax due, then file and pay the amount due as shown on the Form 1040, but expect a bill later from the IRS for the penalty and interest you will owe. Only the IRS will calculate this—TurboTax will not calculate it.
Did you start 2019 this year in 2021?
Online is only good for 2020 now. If you tried to use the Online version for a prior year you should try to clear it out so it's not accidentally filed as a 2020 return or transfers into next year.
Or you can leave this account and set up a new account to do 2020. How to start another return in the Online version
FYI - and when you file 2020 enter 0 for the 2019 AGI since you are filing 2019 late.