That depends---are you in a state that taxes retirement income? Did you have state tax withheld from your retirement distribution? Is there anything entered on your 1099R for that box? If you are in a state that has no state income tax you leave it blank and enter nothing -- not even a zero.
I'm in CA. Yes they tax, and yes, had tax withheld so there is an amount entered into the previous boxes.
I don't have the actual 1099 form, so I'll need to search the web to find.
You need to get the actual 1099R. Ask the company for it or maybe you can log in to your IRA account and download a copy or import it.
You need to obtain an actual copy of your 1099R, both for your federal return and for the state. Many financial institutions make them available to import into the software, or available online for you to print out for yourself. If neither of those is possible for you, then call the bank or financial institution that handles your retirement account. Do not guess at what goes into the boxes. Get the 1099R and enter it exactly as shown---that is what was sent by the financial institution to the IRS and your state.
To enter your retirement income, Go to Federal> Wages and Income>Retirement Plans and Social Security>IRA 401 k) Pension Plan Withdrawals to enter your 1099R.