1, Go to "Sales Order" which has been created while syn order from Shopify.
*Please Take reference How to sync sales order from Shopify
2, Post shipment / shipment & invoice of the Sales Order
3, Go to "Shopify Shop" and select "Sync Shipments" / Search "Sync Shipments to Shopfiy"
-If all items have been shipped, Shopify will show “已出貨"
-If it is partially shipped, Shopify will show ”部分出貨"