State distribution amount (Box 16) in 1099-R for excess ROTH contribution?

I have removed excess ROTH IRA contributions made for tax year 2021 and I am reporting 1099-R for tax year 2021 based on the contributions + earnings (as per instructions in other threads on the same topic).
However, the instructions do not mention anything regarding the State distribution amount (box 16).

Should box 16 kept blank or should I use the amount in box 1 (Gross distribution amount) and mention it in box 16? My state is California and I did not withhold any Federal or State taxes upon removal of excess ROTH contribution. Thanks.