> ## Documentation Index
> Fetch the complete documentation index at: https://spreecommerce-documentation-update-4-5-to-4-6.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Adds item (Variant) to an existing Shipment

> If selected Variant was already added to Order it will increase the quantity of existing Line Item, if not it will create a new Line Item