You can import additional products or export your current product listings at any time within the Canal app under the Listings tab.
To import additional products you'll just click Import in the top right of the Listings page. You'll then be able to download Canal's product template and upload on the same page like you did during onboarding. *It's important to not edit the CSV format when adding your products, this will cause the import to fail.
Once the import is successful you'll see these products listed with your current products for Storefront partners to sell!
When exporting products you have the option to export your entire catalog of products or you can select specific products by clicking the box to the left of the item > Export.
You can learn how to Unlist products here.