To avoid underpayment penalty in 2025 you will need to have paid timely thru the year thru either withholding or quarterly estimated tax, the smaller of either - 100% of your 2024 tax (110% if AGI > 150k), or 90% of your 2025 tax (this is the 'safe harbor' amount). This FAQ is helpful https://www.irs.gov/faqs/estimated-tax
Generally, TT will generate ES vouchers by default using "100/110% of 2024 tax" and assumes your 2025 withholding is the same as 2024 unless you provide a different 2025 estimate. The difference between these is the total ES due, and it gets divided into 4 as underpayment is calculated on a quarterly basis.
So that is probably where the $1440 is coming from, tho if you don't normally pay ES and had a refund in 2024 I am not sure why offhand, it depends on your situation; one scenario if your AGI > 150k then it would calculate ES based on 110% of your 2024 tax which will be too high (unless your tax liability increases significantly in 2025 e.g. Roth conversion).
As @PatriciaV indicates you should be able find the worksheet showing the calculation for these vouchers. Also if on desktop you can go Forms mode and find the "Est Tax Options" worksheet there.
If you go thru Other Tax Situations / Form W4 and Estimated Taxes section you can provide information for 2025 to see if it reduces or eliminates the need for estimated tax. If you are comfortable with your withholding and have a stable tax situation you can also ignore the estimated tax vouchers, but before you do it's worth understanding where these numbers are coming from (you won't get reminders from the IRS about it, you'll simply be assessed an underpayment penalty in your 2025 return if fall below the 'safe harbor' amount).
