You don't upload pdf files. You need to find the other turbo tax saved files which are saved by the program and then upload them. If you completed the previous versions on same computer, turbo tax program should automatically pull them forward into this years program. If from other computer, you manually upload them but pdf version is for your personal use, not for the turbo tax system
Don't transfer from the pdf. It is very limited. Only name and address and personal info. You need to log into the same account to transfer or have the .tax2019 file on your computer.
How and where did you do 2019?
How to transfer into Turbo Tax Online, including from a pdf file or other software or from the Desktop program
If you used the online version are you in the right account?
It's common to end up with multiple accounts. First LOG OUT of whatever TurboTax account you're logged into right now. Then use this TurboTax account recovery website to get a list of user ID's for an email address. Run the tool against any email addresses you may have used
https://myturbotax.intuit.com/account-recovery/
If you used the Desktop CD/Download program then the only copy is on your computer and not saved or stored online.