How do I transfer a 2020 turbo tax file to Pro series tax file?

[Just-Lisa-Now-]

You need it to be a Turbotax Desktop file, you wont be able to transfer from TT Online

https://proconnect.intuit.com/community/convert-data-files/help/how-to-transfer-turbotax-returns-to-...

[Chrysta]

I downloaded the online file to my desktop.  So it is a desktop file with the proper extension.  It's from a new client. I don't have Turbotax software, just Proseries.  From what I am seeing online, I might have to have 2020 Turbotax software to save the file.  That doesn't make any sense.  Why doesn't the downloaded file work?  I'm getting an error message.