From todays meeting, this should help walk you through it to make the edits.

For FBA Barcode Preferences (FNSKU Settings)

To change your default barcode preference between manufacturer barcodes and Amazon barcodes (FNSKU):

1. Go to Settings in your Seller Central account
2. Click Fulfillment by Amazon
3. Locate FBA Inventory Barcode Preference and click Edit
4. Select either Manufacturer barcode or Amazon barcode
5. Click Save

Important notes:

• Allow 24 hours for changes to be fully processed before creating new offers
• This setting only applies to new offers created after the change
• Existing offers cannot have their barcode preference changed through this setting—they must be updated individually or recreated