A tax return that has been filed and accepted by the IRS can only be changed by preparing, signing, and mailing an amended return form 1040X. Do not change your original return until you start the amended return. Wait until you receive the refund (if you are getting one) from the original return before preparing your amended return. Here is help for you: https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
You can't efile an amended return. You must print and mail it yourself. TurboTax does not mail it for you. In normal times, it takes the IRS about 16 weeks to process an amended return.
