No. Online TurboTax is only for 2024 returns. You cannot use online for a past year return.
You could use the desktop software to prepare a 2023 state return on a full PC or Mac, or you could try going on the IL site to get the forms to prepare and mail in. A 2023 return can only be filed by mail.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/printers-printing/finish-prior-year-retu...
If you already paid for your online software you can ask customer support for a download of the desktop software.
They are available from 5 a.m. to 9p.m. Pacific time daily
https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number
https://ttlc.intuit.com/turbotax-support/en-us/help-article/state-taxes/contact-state-department-rev...
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**