I live in wisconsin but worked in illinois and now it says I OWE illinois money, why?

WI and IL have a reciprocal tax agreement for W-2 workers who are working cross-border.

Look at your W-2.    IF it properly shows ONLY WI taxes being withheld, then  you do not file an IL tax return...and on the MY Info page you DO NOT indicate you worked in another state.  and you can then delete the IL tax return in the state section of the software.

_______________________

IF your W2 does show IL taxes being withheld, then you did not file the proper forms with the employer to get IL  withholding stopped (or they did not implement them if you did)....then you would have to file a Non-resident IL ta return to get the IL tax withholding refunded...but you would also need to indicate you had zero IL income to do that on the IL nonresident tax return interview.