We cannot see your screen and do not know what you are trying to do. What documents are you trying to upload--and for what tax year
@Oldscrooge What are you trying to do? You do not send your 2018 tax return to TurboTax. If you still need to file your 2018 return you have to print it, sign it in ink and mail it to the IRS.
Did you start a return for 2018 using online software back in 2019? Here is how to finish preparing it and get it filed. It can only be filed by mail---and YOU have to mail it. TurboTax does not mail it for you.
If you have any changes/corrections at all to make to your 2018 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 5 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.