Yes, you can e-file your 2021 amended federal return in TurboTax, but only some states allow you to e-file your amended state return.
If the IRS has accepted your return, then you will need to wait until you have received your refund, if applicable, and then amend that return to make changes, if needed.
Please see the TurboTax FAQ below for instructions on how to Amend:
How do I amend my 2021 return?
@Captain52
