NOL for 2020 in NY state and federal

I am working on the amendment to my federal and NY state returns for 2020

The AIG is $16,097. TurboTax calculated NOL as the same amount. Since I missed deadline for carryforward/carryback, I assume that  I should  file amendment to 2015 federal return.

 

 

 

Since NY does not follow CARES Act, I am filing IT-558 decoupling form. I am reading the following:

"Your recomputed federal NOL deduction is the amount that your federal NOL deduction would have been if computed using the rules in place prior to any changes made to the IRC after March 1, 2020. For example:
- your federal NOL deduction for losses incurred in tax year 2018 or later is limited to 80% of your current year federal taxable income (computed as if the changes to the IRC after March 1, 2020, did not occur)"

How would I recompute federal NOL deduction? Should I multiply $-16,097 by 80%, which comes to $-12,877? Or, since the taxable income is negative just put 0?

 

Thank you