The event is now triggered from an automation instead of an entity operation — the operation, activity_id, activity_type, and trigger_entity fields were removed, and _event_source and _trigger_source_type are now always automation (breaking)
ticket, event_attachments, _trigger_source_type, and _trigger_source are now always present; event_attachments is always sent but may be empty when the request carries no files, and _trigger_source identifies the automation execution and action that triggered the request