Facebook Messenger, Send a Message action, Recipient issue

Hello, I’ve setup a trigger using HARPA AI, that monitors certain text appearances on a given page. I’ve added a facebook Messenger module too using the Send a Message action. When I open to configuration page for the Messenger action, I’m seeing a ‘Recipient’ section with a ‘Page Scoped Used ID’ field. I want to send a message to a Facebook group chat whenever the first module is triggered but I don’t know what to type here.

Also, what should I pick in the ‘Messaging Type’ field? The options are: Response, Update, Message Tag.