Go to CopeCart Marketplace, find a product you'd like to sell and click on the Promote button:
If the Vendor approves affiliate requests manually, you'll have to wait for approval before you can receive an Affiliate Link:
If the Vendor accepts affiliate requests automatically or has already accepted your request, just click on the Copy URL button to get your personal Affiliate Link for the product:
That's it! Now use this copied link to promote a selected product.