Congratulations! Since your due date is so close to the end of the year, you should not add the dependent to your W-4 calculations just to be safe. That way your not accounting for any extra credit and shorting your self on withholdings. If the baby is born before Jan 1, 2025 then you will claim the child as a dependent for the entire year and depending on your income, may qualify for Child Tax Credit and/or Earned Income Tax Credit which in turn will lower your tax liability possibly resulting in a higher refund.
You can use the TurboTax W-4 calculator to help you complete your W-4.
https://turbotax.intuit.com/tax-tools/calculators/w4/
