I purchased the program to file an amended 2019 tax return but I was never able to access the program.

Did you use TurboTax to prepare your original 2019 return?   Or was it prepared elsewhere?  Why did you purchase 2019 to amend?   If you used TT to prepare your 2019 return you do not have to pay again unless the changes you are making require an upgrade to a higher version of the software.   Please explain so we can help further.