Go to Walmart and view the product that you want to sell and view its Page Source. It may look different on different browsers and computers, but you should be able to right click on the page to see the drop-down menu. Select View Page Source– be sure not to click on the image when doing this, try to click somewhere in a spot on the page where there is no text or any other element.
This will open a page with the web site’s source code. Click CTRL+F (or Command+F on Mac) and search for the word “UPC” to identify the UPC code for the product:
Edit your product on GeekSeller, and insert the new UPC code. Then select “Additional Attributes” tab. In this section add the attribute: ProductIdUpdate with the attribute value Yes
Go back to edit a product tab, delete the ProductIdUpdate attribute (you don’t want to send it every time you update SKU) and click Save without Exporting to Walmart, to just make the change in the GeekSeller database.