The 1040X is not final yet for 2019. Look under Common Forms, "Cant find a Form" put 1040X in the box, click on the form and it will show up in the return. Make sure you save the original return and save the Amended as a "Save as" return so you will have both. Don't start anything until you save the Original by renaming the Amended and don't forget to go to the state also, if it is being amended, as a result of the IRS amendment.
As mentioned, you can not E-file an Amended return, only by mail and you probably want to wait till later in the tax season anyway.
I know what you mean. I have 2 filed that just received 3rd party sick pay w-2's, which the employer told them and me, that it would not be taxable because the employee paid the full premium and no employer paid portion. Thinking a new bookkeeper might be in order 🙂