Are you using Windows or a Mac. In 2022 TurboTax in Windows I am able to override. But as I said, not all entries can be overridden. It might be more accurate to say that many or most entries cannot be overridden. If you can't override a value that comes from another form, you might have to work back to where it comes from.
If you make several overrides, your estimate is essentially worthless because you are preventing the TurboTax calculations from working properly. If there's nothing particularly unusual about your tax return, you should not need overrides to do an estimate. You should be able to enter your information in forms mode in the places that are designated for manual input. Or you might actually find it easier to use the Step-by-Step interview.
An override is not just an entry. It's changing an amount that TurboTax has calculated. You shouldn't need to do that. And overriding what TurboTax has calculated reduces or completely destroys the accuracy of your estimate.
