It is not possible to use wing sexing. Ameraucana do not possess either of the required genes for accurate wing sexing.
An exception is with large fowl black Ameraucanas at Cackle Hatchery. Over the past couple years they have been developing "parent" flocks so their day-old chicks can be wing sexed.
I'm sure they will offer this option with their other varieties of Ameraucanas also (if not already), but it takes time to first develop the segregated parent flocks.