Did you already file it?
If your return rejects for something you can fix it and resend it. If it is accepted you will have to amend. So don't change your return until you know.
You should not amend until the first return has fully processed and you get the first refund or your tax due payment has cleared.
The 2021 1040X amended return won't be ready until February 25
See,
Federal Individual Forms Availability
How to Amend
https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-...
