Under Can I e-file my 1040X to amend my return the first sentence reads
"Your 2022, 2021, or 2020 federal Form 1040-X amended return may be eligible for electronic filing if the original return was successfully e-filed using TurboTax." Since I have the same issue with not being able to enter today's date for my signature, it appears that either TurboTax 2021 has a bug or the person who wrote the article on e-filing an amended return is wrong.
