Your batch payload must specify at least distinct_id or to while firing a notification event.
If the payload contains:
- Option 1: ONLY to (and no distinct_id) - the event uses all destination values from the to object (as it is).
- Option 2: ONLY distinct_id (and no to) - the event uses all destination values (such as SMS, WhatsApp, Email, Push, Voice and so on) from the user’s profile and sends the notification.
- Option 3: BOTH distinct_id and to - the to and distinct_id channel data merges (to object take precedences) and sends the notification. The sent notification is tagged to the ID specified, which can be then used to search the logs by using distinct_id.