To activate the handover protocol, a Page must have only one app with the Primary Receiver role and at least one app with the Secondary Receiver role. By default, the Primary Receiver app gets control of the conversation.
To assign app roles for your Page, do the following:
Once a role is assigned, each Facebook app will automatically be sent an app_role webhook.
{
"recipient":{
"id":"<PAGE_ID>"
},
"timestamp":1458692752478,
"app_roles":{
"123456789":["primary_receiver"]
}
}
For complete details and event properties, see the app_role
Webhook Event Reference.