If you don't want our software to automatically assign barcodes for you, you can deactivate this option in the Settings.
How do I assign barcodes to specific products? (Shopify Only)
You can then assign barcodes manually by clicking on the More actions > Assign barcode option available on the Product page, Variant page, Products list page.
You can then assign barcodes manually by clicking on the More actions > Assign barcode option available on the Product page, Variant page, Products list page.