iOS plugin code event

Hi, How can I use events in iOS native plugin? In my code plugin.m I'm creating object and add event like a:

 - (void)beaconManager:(id)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLBeaconRegion *)region
 {
     NSLog(@"TEST RANGE");
     CLBeacon *firstBeacon = [beacons firstObject];
     NSLog(@"%f", firstBeacon.accuracy);
 }
 

In Unity C# code I use function from native plugin which create object and declare event, but NSLog never print "TEST RANGE".