If you can't download the pdf file from Online you need the 2021 program installed to open the .tax2021 file. Did you use the Desktop installed program for 2021?
Or You could try the TaxPrinter service (not connected with Turbo Tax) to convert a .tax file to pdf at
http://www.taxprinter.com
They might be expensive and it is probably not safe to email tax returns back and forth.
OR get a copy from the IRS -
http://www.irs.gov/Individuals/Get-Transcript
