Step-by-step: copy the public Google product feed URL from Shopify for auditing with FeedScrub.
In Shopify admin, open Settings → Apps and sales channels (or the Google & YouTube channel). Open feed or product sync settings and look for a scheduled feed / supplemental feed URL.
The URL should be publicly reachable over HTTPS and return XML (RSS or Atom) with g: product tags. Paste it into FeedScrub. If Shopify only offers a private/authenticated feed, export XML and upload the file instead.
See also our Shopify disapproval guide for common policy issues that appear after you locate the URL.