Alert to be included in the message. This may be a string or an object of
Badge to be displayed with the message. Set to 0 to remove the badge. When not specified, the badge will remain unchanged.
Type of the notification.
Specifies whether to configure a background update notification.
Specifies whether to set the
mutable-content property on the message
so the clients can modify the notification via app extensions.
Sound to be played with the message.
An app-specific identifier for grouping notifications.