ReadonlyapplicationThe applicationServerKey read-only property of the PushSubscriptionOptions interface contains the public key used by the push server.
ReadonlyuserThe userVisibleOnly read-only property of the PushSubscriptionOptions interface indicates if the returned push subscription will only be used for messages whose effect is made visible to the user.
The
PushSubscriptionOptionsinterface of the Push API represents the options associated with a push subscription. Available only in secure contexts.MDN Reference