Options are :
1) use a local tax professional
2) find a family member or friend who has a compatable computer you can borrow or buy a newer model
3) get the forms/instructions from the fed/state and fill them in manually
For the program you cannot use ... if you paid for it return it for a refund if you can. If you bought directly from TT follow these instructions : TurboTax CD/Download Refund Request Form to request a refund if still within 60 days of purchase.
If you can't install Turbo Tax Desktop program you can transfer from your 2021 return from your computer into the online version. You need to have the file ending in.tax2021 on your computer.
If you used the Desktop program last year here’s How to transfer into the Online version, expand the blue link if you used the CD/download last year
If you used the Desktop program before you may notice several differences and not like the online version. It has less features and no Forms Mode. You can only do 1 return. Federal and state are separate fees.
Your return is only saved online so be sure to save both the .tax2022 data file and the pdf file to your computer when you are done. In case you need to amend in the future or if you need a copy to get a loan or something. You might not be able to access your online return when you need a copy.
To use the Online version you would have to start over in a new online return and pay for Online separate from the Desktop program. Then try to get a refund for the Desktop program.
Oh I misread your question. I thought you were asking about the 2022 new program. What OS is your Mac? Did you buy the right year program?