An installation code for what exactly?
The TurboTax license code for tax year 2019 desktop software was 14 digits.
The TurboTax license code for tax year 2020 desktop software is 16 digits.
Not sure what code you received. There has never been a 20 digit activation code. The codes for 2019 were 14 digits; for 2020 software it is a 16 digit code. 2019 was the first year for those license codes.
To find your license code:
https://ttlc.intuit.com/community/tax-topics/help/i-can-t-find-my-license-code/01/852973
Unable to install TurboTax 202 Delux
neef 26 digit license code not in my purchase
@charlene425 For assistance in locating your license code, please see this TurboTax FAQ: I can’t find my license code