Follow the directions in the related answer below provided by a fellow TurboTax agent.
https://ttlc.intuit.com/replies/6256459
You will need to mail your return to the address listed below that applies to your situation.
If no payment is enclosed, mail your return to:
Illinois Department of Revenue
Springfield IL 62719-0001
If a payment is enclosed, mail your return to:
ILLINOIS DEPARTMENT OF REVENUE
Springfield, IL 62726-0001
What paperwork should I send with Illinois return. I do not owe money. 1040? 1040SR? 2019ICR?
You would send the 1040 and all supporting forms and schedules. For example for a 1040, you will find a number in the upper right hand corner of the forms. The is the sequence number that directs the order of attachement. You will also need to attach W-2, 1099-R and any form with withholding. IL may request a copy of your Federal return. It will tell you so on the IL form.
If it is a worksheet, it will indicate that it is just for your records.
This information is out of date. Best to check the http://tax.illinois.gov website to be sure, but the latest addresses as of 4/3/2023 can be found at this link:
https://tax.illinois.gov/questionsandanswers/5.html
All the best!