The most likely reason is that you don't have any tax to offset.
Windows and insulation are claimed in Part II of Form 5965. You'll only receive a credit if you have income tax that it can offset. If your tax is zero, or has been reduced to zero by other credits, the credit can't offset any tax.
Also, if you've already claimed a credit for windows after tax year 2005, you may not be eligible for another credit. There's a combined credit limit of $200 for windows for all tax years after 2005. See Energy Efficient Home Improvement Credit (Part II) in the Instructions for Form 5695 (2022) for more information.
