Setting the Base Collection
You can generate a unique feed for any Shopify collections
You can specify which collection to use as the basis of your feed. You can use this to generate multiple unique feeds for different collections. This will override the setting from the apps dashboard.
Query string (what's that?):
XXX is the collection handle. You can find that handle by visiting the collection page on your store front. It should be the last part of the URL you see in your browser address bar.
Alternatively you can specify the collection by its ID:
YYY is the numeric id of the collection. You can find that ID when you visit the collection in shopify admin. It should be the last part of the URL you see in your browser address bar.
Note: The collection’s visibility needs to be enabled for “Online store” in order to be used as the basis of the feed.