Hi @boazizh,
Thanks for reaching out. Happy to help you with this!
The feed file is generated every 15 minutes and, in version 1.11.x of the plugin, was needed for Facebook to pull in the product data for your catalog.
The file is located in your “/wp-content/uploads/facebook_for_woocommerce/” folder and starts with “product_catalog_”.
However, you do not need to upload this and, with version 2.x of the plugin, it is not really needed at all.
Would you please share which version you are using? Would you also please tell me a little bit more about your site and why you think you might need to upload this file?
Thanks,
Marcus