Note that only active schools (with unexpired book licenses) will be displayed by default in the Stores list. Once your school no longer has any active books, you may still view their storefront listing, but not access it.
Click on the menu icon in the top right corner to make inactive schools visible.
Once turned on, the filter will be applied to showing a list view of expired storefronts.
Click the x in the filter to return to the active school list.