Basically the total tax you owe minus the tax withholding a throughout the year needs to be at least 7.5k to claim the full credit.
Example, you make 200k and owe 25% tax which is 50k. Throughout the year you had federal withholding add up to 40k, so now you owe 10k (50k minus 10k). If you qualify for this credit, you now owe 2.5k (10k minus 7.5k).
The unfavorable way this turns out is your federal withholdings add up 50k, at which point there is no tax owed for the credit to offset. You will not get a refund for 7.5k since it’s a non-refundable credit.
So you should really change your withholding to where you will owe at least 7.5k to claim the full credit. Use your w-4 form to update your witholdings