TurboTax Online supports Form 2210. The penalty is automatically calculated when you owe at least $1,000 and haven't made your minimum required payment. You can choose to have the penalty included in your return or have the IRS calculate the payment and send you a bill.
If the underpayment penalty wasn't added to your return and the IRS assessed the penalty later, it's possible 1) you chose to have the IRS calculate the penalty or 2) the IRS adjusted your tax liability which then made you subject to the penalty.
However, if you paid your 2023 tax liability after April 15, 2024, it's possible that the penalty was a failure to pay penalty. The failure to pay penalty is assessed when the balance due on your tax return isn't paid by the due date.
