One of two ways I think.
Schedule 1299-C is for Income Tax Subtractions and Credits.
First, under View>Forms, click on Open Forms. Open 2022 Illinois, scroll down until you find Schedule 1299-C. You can open directly there.
Alternatively, if you are using the Step-by-Step menu, under Credits and Taxes, there is a section called Business and Investment credits. If you have any of those credits, after you fill in the information requested, it will populate Schedule 1299-C with the necessary information, if that is the appropriate schedule to use. Then you should see Schedule 1299-C under View>Forms.
Hope that helps
