The PushManager.getSubscription() method of the PushManager interface retrieves an existing push subscription.
The permissionState() method of the string indicating the permission state of the push manager.
Optionaloptions: PushSubscriptionOptionsInitThe subscribe() method of the PushManager interface subscribes to a push service.
Optionaloptions: PushSubscriptionOptionsInit
The
PushManagerinterface of the Push API provides a way to receive notifications from third-party servers as well as request URLs for push notifications. Available only in secure contexts.MDN Reference