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It sounds like the error message you're seeing is indicating that the ability to use Facebook or Instagram checkout is not available in your country. If you want to use Facebook or Instagram checkout, you will need to select a different country.
"Catalog is already connected and owned by business account", when a catalog is already connected and owned by a business account, it means that another account has already connected a catalog to their Facebook business account. You can not connect multiple catalogs to the same business account.
To solve this issue, you can disconnect the catalog from your Business Manager, by going to the Business Settings of your account, then to the Catalogs Tab, and looking for the catalog you want to disconnect.
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