For one you cannot amend a 2019 tax return that has not yet been filed and accepted by the IRS. The IRS will not be accepting a 2019 tax return until on and after January 27. Your federal tax return, Form 1040, has been finalized for filing.
Second, the Form 1040X for amending a tax return that has already been filed and accepted by the IRS will not be finalized and available until 01/29/2020.
