If your listings in multiple sales channels have different SKU numbers for the same item, you would need to merge/link these listings into a master SKU. Initially, when these listings are downloaded into Selro inventory separate products will be created in the inventory. You can either manually upload or upload via a CSV file.
For bulk merge please refer to the article
You can also manually merge items by searching items in the inventory and click 'Merge Product'.
Once merged, you can un-merge the listing by editing the product and select 'Listing Tab'
Next, you can click 'Other' and then 'Un-Merge'
This will un-merge and create a new product with the listing SKU in the inventory.