Where do I add the additional 2023 federal taxes that I had to pay when I filed my return in 2024, to the 2024 return? found the section for State, but not for Federal

A federal tax due you paid in 2024 for a prior year does not go anywhere on your current tax return.  Each year is completely separate.  You only enter the state refund because it might be a federal deduction if you itemize on Schedule A and don't take the Standard Deduction.  

Any Federal balance due amount that you paid in 2024 for the 2023 tax return is not entered as part of your 2024 return.  Unlike state taxes, the Federal tax that you paid is not a deduction.  

You only enter any Federal estimated payments that were made during the year so that you get credit for those when determining your overall refund or balance due.

@pajofa