Facebook Business Transaction Manager
Helps you manage your catalog and sales on Facebook and Instagram Anyone can use a business transaction manager to create and manage a catalog that includes all the items they want to promote.
Step 1 :Log in to the Business Transaction Manager
Step 2 :Press onCatalog
Step 3:Press onAdding products
Step 4:Press onAdded manually.
Step 5 :Go back to your store so you can complete the steps.
You can follow the steps here.