This article will teach you how to link listings to inventory automatically
Listings must be linked to inventory in order for Inventory Sync to work properly.
Linking during a Listing Import
When running a listing import from your sales channels, Sellbrite will give you the option to automatically build products from your existing listings (some channels don't provide this option). This option is commonly used when first setting up your Sellbrite account. This means that Sellbrite will pull the product information (images, title, description, etc.) from your listings and create products in your inventory, which will represent what you physically have on hand and house your inventory quantities.
The auto-build function will also retrieve your listing's SKUs which will automatically link your listings to the newly built products. In other words, enabling this will ensure that your listings are linked.
If you've built products in your inventory from a product spreadsheet or a previous listing import, you can choose to disable the auto-build feature. Running a listing import will automatically link your new listing to products in your inventory if your SKUs are an identical match. If the SKUs in your listings are inconsistent with the SKUs already in your inventory, your listings will remain unlinked and you will need to link them manually.
More on manually linking listings, here: Manually Linking Listings