For many Shopify themes, multiple urls of the same product listing are created based on how they are nested (e.g. under a product category or collection).
Because this results in many duplicate pages, a canonical URL is usually set from the collections pages to the direct product url.
Canonical URL path:: /products/
Non-canonical URL path: /collections/*/products/
Here is an example of a direct product URL:
Here is the same product linked on a collections page. Note the difference in URL. By default, they link to the non-canonical version of the pages.
And the collections URL loads a duplicate page. The canonical set for the collections page references the /products/ page as the canonical.
This way of linking products in Shopify websites often results in the direct product URL having no incoming internal links or backlinks. Only the non-canonical duplicates of these product listings are linked in collection pages.
How to solve
The fix is to link directly to the /products/ pages, in some way. Here are a few solutions that other Shopify stores have used:
Change collection pages to link the canonical URLs by default. Here's a discussion on how to do so that we found on the Shopify Community Forums.
Other suitable solutions may exist depending on the setup of your Shopify store, so do check with your technical team or with the Shopify team.