If you were eligible for the child tax credit on the 2023 tax return that you completed and filed, the program would have told you that you received the credit and the credit would have been included on the 2023 tax return that was filed. It would be included in your federal tax refund or it would have reduced the amount of taxes owed.
Look at your federal tax return, Form 1040 on Line 19 for the Child Tax Credit and on Line 28 for the Additional Child Tax Credit.
