I am claiming the $300 charitable deduction for 2020. It's asking me how much I want to enter for new york.

​​​​​​The deduction of $300 in charitable contributions, on top of a standard deduction, is a deduction for the federal level only. This amount is required to be added back to income for NY purposes. 

Per NYS, if you claimed this contribution on your federal taxes, then enter the $300 to add back that amount in NYS adjustment. 

@LenaH Thanks, just to clarify, in the NY portion, it says

"Enter the New York portion of the charitable contribution deduction" is that 300 under New York source? Or zero? The instructions are not clear at all 

The New York portion of this contribution would be $300. The $300 will then be an adjustment to your federal gross income on the new NYS Form IT-558 under code A-003, New York State Addition Adjustments.

@sarahmoore620