Did you already file using the Standard Deduction? And want to change to Itemized Deductions?
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 this year
https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-federal-tax-return-curr...
