To add items automatically from your website to your retargeting Meta catalog and Google Merchant Center, you need to add microdata tags to your Meta Pixel and Google tags installation.
Microdata is the structured retargeting markup data used to indicate key information about the items on your website, such as names, descriptions and prices.
Please check now by enter a URL for a web page with inventory details.:
https://business.facebook.com/ads/microdata/debug
PRODUCT CATALOG DEBUG TOOLS
Pixel Debug Tool