Pure Arrow rules apply.
Digits along an arrow must be a combination of, and sum to the total in the circle.
For example, if the sum is 12, you must use any combination of 1s and 2s along the arrow that sum to 12.
Like so: (12)-1-2-1-2-1-2-1-2 or (12)-2-2-2-1-1-2-1-1 etc
Solution code: Column 4, 6