Track packaging


I’m looking for someone to help me with tracking packaging and shipping boxes

What i’m trying to do is to add second child table in which I would like to select shipping boxes for delivery. Basically same funcionality as with items - Select item and on delivery Note submit, it gets deducted from stock. I’ve already duplicated Delivery note item table, but stock of the items in that table is not updating. What is the script to update stock of item?
Is there any other way to track packaging?