Have 2020 installed on laptop from CD, but no longer have box. How can I get my license key?

I need to amend my 2020 return but I have changed laptops since I filed.  I have all of the boxes and CDs going back to 2015 EXCEPT 2020.  I cannot find it.  I have the files to install the 2020 version on my backup of my old laptop, but do not have the license key I need to use it.  Is there any way to get my license key from TT?