whitelisted_domains - Messenger Platform - Documentation - Facebook for Developers
Messenger Profile API whitelisted_domains is a property of the Messenger Profile API. For information on retrieving, setting, updating, and deleting whitelisted_domains, see the Messenger Profile API Reference. The whitelisted_domains property of your bot's Messenger profile specifies a list of third-party domains that are accessible in the Messenger webview for use with the Messenger Extensions SDK, the Checkbox Plugin, and the Customer Chat Plugin.