Need your advice to sort out below.
below is the structure I have defined in Message Mapping.
If Order Item - J_3APOSNR is "Blank" then item_key = "some value".
I defined my mapping as below
this is working fine as long as I pass "J_3APOSNR" value blank ..
But If I set some values to "J_3APOSNR" and repeat "order item" header node more than one , showing an error that item_key cannot be created.