Should full roth conversion box be checked on 1099-R if I did a backdoor Roth?

Turbotax is flagging: full roth conversion box should not be checked unless there is an amount on line B4 (1099-R). I did a Backdoor Roth and I am not sure if this box should not be checked. Currently it is checked.  Do I unselect it or keep it selected? Thank you.  Samantha