At your discretion, you can add products that will or will not be displayed in the Google feed link.
To do this, you need to go to the admin panel of the site "Products / Catalog"
And if you want to add the product to the Google feed link, you need to make the "active" categories in the "Status" column (a small gray circle should turn green)
or individual products
Accordingly, if you do not want to add certain products, then you need to deactivate the status (the small lace should be gray).
A couple of nuances:
1) if you make an active category, and the products in it ALL are inactive, then the products will not be added to the feed link
2) if the category is inactive and the products in it are active, then both the category and products will NOT be shown in the feed link
3) if the category is active and some products are only active - only active products will be displayed.
You can read Google Shopping setup instructions HERE