How come when I enter in the amount of childcare expenses (~4500$), it does not increase the amount of my refund?

Childcare expenses are not a credit, they are a deduction. A deduction reduces your taxable income, it doesn’t add directly to your tax refund. Also, they are non-refundable, so if your income before you added the expenses is zero, or you were already getting a refund before you added them, you will not see any changes to your refund.