File amended tax return

Brokerage firm has advised that they will be sending a revised 1099.  I have already filed my taxes for 2025 and they have been accepted and I have received refund.  Now that I have to file an amended return due to brokers error, I cannot find the ability to do that on turbo tax due the following instructions:

 

In TurboTax Desktop:

  • Open your original .tax file

  • Go to Online → Amend a Return (1040‑X)

There is no option available to select Amend A Return (1040-X) Please advise.