If you use Shop Application for your e-commerce solution, this is how you can create your product feed.
To export your catalogue or generate a feed URL, go to the "Marketing" tab. To find the export for Google, click on "Price Comparison sites":
Next to "Google"(XML file), you simply need to click on the "Add" icon:
You can then select the entire product catalogue or the individual sections you want to export. Once the different steps have been validated, click on "Create file". A URL will be generated containing the feed to export your products: