location disabled from Privacy->Location Services -> off in iPhone

How to add custom message if location disabled from Privacy->Location Services -> off. I am using iPhone11 and getting apple issues as to add description about application if disabled also. Please suggest.

You can do something like this in your locationManager class.

func checkLocationServices() {
    if CLLocationManager.locationServicesEnabled() {
        setupLocationManager()
        checkLocationAuthorization()
    } else {
        // Show alert letting the user know they have to turn this on.
         self.delegate?.showLocationServiceDialog(status: 2)
    }
}

func checkLocationAuthorization() {
    switch CLLocationManager.authorizationStatus() {
    case .authorizedWhenInUse:
        locationManager?.startUpdatingLocation()
        break
    case .denied:
        //I'm sorry - I can't show location. User has not authorized it
        self.delegate?.showLocationPermissionDialog(status: 0)
        break
    case .notDetermined:
        locationManager!.requestAlwaysAuthorization()
    case .restricted:
        // Access to Location Services is Restricted", message: "Parental Controls or a system administrator may be limiting your access to location services. Ask them to.
        self.delegate?.showLocationPermissionDialog(status: 1)
        break
    case .authorizedAlways:
        locationManager?.startUpdatingLocation()
        break
    @unknown default:
        print("Unknown permission status")
    }
}

In function checkLocationServices() you can show alert to the user if CLLocationManager.locationServicesEnabled() returns false.