I'm not specifically familiar with your state software. The following is a "generic" answer.
There is no federal deduction for making a contribution to a 529 plan. Some states allow a deduction on the state return. If your state is one, it will come up in the state interview; usually in the "Here's how (your state) handles income differently" section.
Here's an older post on how to do it for IL: https://ttlc.intuit.com/community/college-education/discussion/where-in-turbo-tax-can-i-deduct-illin...
