As you navigate through the New York state interview in TurboTax, you will eventually come to a screen with the title, "Take a look at New York credits and taxes".
On this screen look down to the subheading, "Other Tax Credits", then click on Start for "Employer Compensation Expense Program Wage Credit".
Go through this sub-interview and answer the questions about ECEP. Form IT-226 will be generated from your answers, if you qualify.