@auntiewild701  In case you ask why you can't e-file 1040X for 2019 returns not previously e-filed by you (and you wouldn't be the first one), it's not an IRS restriction but by Intuit's own software limitation.

There are other tax products out there that can e-file 2019 1040X regardless of whether it was previously e-filed with their own programs but this is just not possible with Intuit's professional tax products.