Letter code in box 12 of my W-2 is NY PFL, but I do not see it in the drop-down menu to select it. What should I select instead if anything?

I am not referring to box 14. Box 14 has different code in it. I am referring to box 12.

NYPFL is normally reported in box 14.  The reason it goes in box 14 normally is so it flows to Schedule A, line 5a. 

Unless you have 

• $12,000 for Single or Married Filing Separately,

• $18,000 for Head of Household,

• $24,000 for Married Filing Jointly or Qualifying Widow(er),

It doesn't matter elsewhere on your return.

Here are the only codes allowed for box 12:

Box 12 Codes

Are you referring to an entry in box 14 (the premiums paid for the NYPFL) or are you referring to income that you received from the PFL program? The benefits (income) from PFL are generally taxable for federal and state purposes - see https://taxnews.ey.com/news/2017-1476-new-york-paid-family-leave-benefits-are-taxable-contributions-must-be-made-on-after-tax-basis

If you mean the box 14 entry, then go ahead and use the "Other mandatory state or local tax not on the above list" category. This flows through to Line 5a on Schedule A. 

I am not referring to box 14. Box 14 has different code in it. I am referring to box 12.