Definition
Push API defines PushManager
[Exposed=(Window,Worker), SecureContext]
interface PushManager {
[SameObject] static readonly attribute FrozenArray<DOMString> supportedContentEncodings;
Promise<PushSubscription> subscribe(optional PushSubscriptionOptionsInit options = {});
Promise<PushSubscription?> getSubscription();
Promise<PermissionState> permissionState(optional PushSubscriptionOptionsInit options = {});
};