Did you already file your 2023 tax return? If so, why are you filling out Form 2210 now? Form 2210 has to be attached to your tax return. You cannot file it separately.
Did you receive an IRS notice telling you to fill out Form 2210? If so, follow the instructions in the notice for what to do with the form.
If you are filling out Form 2210 on your own initiative, and you have already filed your tax return, you have to file an amended return and attach the Form 2210.
You can fill out Form 2210 in TurboTax. Follow the instructions that DoninGA gave you to get to your tax return. Then type "penalty" (without the quotes) in the Search box and click the link that says "Jump to penalty." Or go to Federal Taxes > Other Tax Situations and under Additional Tax Payments click the Start or Update button for "Underpayment penalties."
