Function onUnregistered

onUnregistered(
messaging: Messaging,
nextOrObserver: NextFn<string> | Observer<string>,
): Unsubscribe
Subscribes to Firebase Installation ID (FID) unregistration events.

Requires Installation ID messaging opt-in. Fires only after a successful unregister() and does not replay to a late subscriber.
Parameters
- messaging: Messaging
- nextOrObserver: NextFn<string> | Observer<string>
Returns Unsubscribe
- Defined in index.ts:810