Just to add to what others have said, itís a tax credit. It covers the first $7,500 of your 2019 taxes, that you file in 2020. Thereís nothing to do with withholding. This is about your tax obligation when you file. Your withholding happens so that you donít get a financial shock when your taxes are due.
If your obligation to Uncle Sam is $7,500, the tax credit covers that for you. If your obligation is more, the tax credit covers the first $7,500 of it. If your obligation is $6,500, the credit only covers $6,500 for you.
Look at line 15 of your 1040. Thatís your tax obligation for your most recent filing. If not much in your life changes, itís reasonable to expect next yearís filing to be similar.