...
Go to SFS Packing Screen → Configurations
Turn on the “Capture External Item Id in pack by Picklist ID/Order ID” toggle switch.
...
You Users will see that a text field to capture the External Item ID of the item is made available on the screen under Picklist ID as well as under Order ID tabs.
...
If the user wants to skip scanning the SKU barcode, Go to Configuration on the Packing screen and turn on the “Skip Client SKU Scan“ toggle switch
...
The field to scan the Client SKU ID will be disabled
...
The user can then just scan the External Item ID to pack the item.
...