No charge if you used Turbo Tax to file the original return. You should not amend until the first return has fully processed and you get the first refund or your tax due payment has cleared.
How to Amend
https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-filed/00/25588
Today is likely the last day to e-File a 2021 Form 1040-X but only if you e-Filed 1040 with TurboTax.
@lil1dre2