did you enter the April payment under Deductions & Credits / Other Income Taxes / Payment with 2024 Federal Extension
April/extension aside did you have a penalty due to underpayment in 2024, if you didn't withhold enough or pay timely (quarterly) estimated taxes to meet the safe harbor amount (smaller of, 100% of your 2023 tax [110% if AGI > 150k], or 90% of your 2024 tax)? Paying it all by April does not avoid a penalty if you didn't pay enough thru the year - underpayment penalty is calculated on a quarterly basis thru the year.
If your income was uneven during 2024 and you had some sort of large income event late in the year such as Roth conversion or cap gains, you may be able to reduce the penalty by adopting the "Annualized Income" method on Form 2210, tho if you simply underpaid in 2024 it will not entirely eliminate it.
If you can provide more information on your situation based on the above then it will be easier to provide more guidance if needed.
