NH DP-10 Line 4

An amount ($540) is listed on line 4 and I am asked for a reason code. I cannot find the amount on any of my 1099s or K1.  I also cannot get to the source of this number.  Does Turbotax calculate numbers (i.e. it would not show up on my 1099s)?  How do I find this $540 to give it a reason?