Expanding on what the others have said, the code that must be entered into TurboTax is whatever code the financial institution puts in box 7 of the Form 1099-R. You do not use something different.
A Form 1099-R for a distribution from a traditional IRA that is converted to Roth will have code 1, 2 or 7 in box 7 depending on your age and how the Roth conversion is performed.
