The federal amended return for e-filing will not be available until the IRS has all their systems updated and have verified that the software companies have complied with the requirements for e-filing an amended tax return.

A date is not yet available.

Go to this IRS news website for information - https://www.irs.gov/newsroom/irs-announces-form-1040-x-electronic-filing-options-coming-this-summer-...

The tentative date for the IRS to start accepting e-filing of Form 1040-X for 2019 is August 17. TurboTax has not announced a date when this capability will be available in TurboTax.