I answered wrong to the qn "At any time in 2021,did you receive, sell, exchange, or otherwise dispose of any financial interest in any virtual currency?" How to fix this?

You may be able to change the answer to that question in the interview.   To get back there (it is not on the list as you have probably noticed), you will have to return to the Income and Expenses list.   

Sign in to your return and click on Pick up Where I left off

Click on Federal on the left menu

Click on Income and Expenses at the top

Scroll all the way down and click on Wrap Up Income

Click through the upgrade offers and the natural disaster questions

After that, you will get the virtual currency question

If you don't get prompted with the question, that means you have entered something into TurboTax as a crypto transaction, so review your 1099-B and capital asset transactions in the Investment Income section of TurboTax if you don't see the prompt after the natural disaster question(s).   

Page 17 of  the IRS Form 1040 Instructions read:

"A transaction involving virtual currency does not include the holding of virtual currency in a wallet or account, or the transfer of virtual currency from one wallet or account you own or control to another that you own or control. If your only transactions involving virtual currency during 2021 were purchases of virtual currency for real currency, including the use of real currency electronic platforms such as PayPal and Venmo, you are not required to check the “Yes” box next to the virtual currency question."