You should have paid your federal tax due when you filed your tax return or by the due date of the tax return at the latest. Please see this link from the IRS for more details on how you can pay your tax due. If you have an existing payment plan for a prior year, it does not carryover to a following tax year unless you make a request to do so.
If you wanted to set up/revise a payment plan with the IRS, please see can I set up a payment plan for my taxes for more details. When going to the IRS website, be sure to select Apply/Revise as Individual to update your payment plan to include the taxes due for your 2024 income tax return.