OptionalchannelThe user's channel data.
OptionalcreatedThe user's creation date.
OptionalcustomCustom user properties.
OptionalemailThe user's email address.
OptionalnameThe user's display name.
OptionalphoneThe user's phone number.
OptionaltimeThe user's timezone for scheduled notifications.
The user ID.
Parameters to upsert and inline-identify a user, ensuring they exist before notifying them.