Create a Catalog Data Feed File :
Step 1 : To upload your catalog to Facebook, you must collect all of your products into a single data feed file with a specific format (CSV, TSC, RSS XML, ATOM XML)
Regardless of the format you choose, there are certain fields that are required for each :
1 - product :
2 - availability
3 - condition
4 - description — Product description; maximum 5,000 characters.
5- image_link — Image URL for this product. Must be at least 500x500px.
The image is cropped to match the required aspect ratio for different placements.
6 - link — Your website URL where a person can view more details about this product.
7 - title — Title name of this item, up to 100 characters.