The federal amended tax return, Form 1040-X, for tax year 2021 is estimated to be available in TurboTax on 03/17/2022
If you e-filed the 2021 federal tax return and it was accepted by the IRS then you can e-file the 2021 federal amended tax return, Form 1040-X, after it becomes available in TurboTax.
If after completing the amended tax return and there are taxes owed, you can pay the taxes owed electronically on the IRS payment website using Direct Pay - https://www.irs.gov/payments/direct-pay
