The software adds this form automatically as needed. TurboTax uses an interview format so that you don't need to update the forms. This form isn't filed separately; only with your state tax form. The state starts with a subtotal from your federal return and then allows for additions and subtractions for the state tax. This is a form for reporting additions and subtractions that aren't otherwise listed on the main NY state return.
The software asks about all tax situations specifically, but it is also flexible to allow for other situations. When answering your state tax questions, the software will ask "if you have any other adjustments to federal" and you can enter any you're qualified to take. Learn more in the instructions for the form here: https://www.tax.ny.gov/pdf/current_forms/it/it225i.pdf
I could do this by going to the 'Forms' view (top left), opening form IT 201 (NY State return), then clicking on line 31. This brings up form IT 225, which can be filled by double clicking on appropriate fields.