如何在当前位置设置MKMapView地域并跟随用户位置？

import MapKit

class ViewController: UIViewController {
    var mapView: MKMapView!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView = MKMapView(frame: view.bounds)
        view.addSubview(mapView)
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    
    mapView = MKMapView(frame: view.bounds)
    view.addSubview(mapView)
    
    let initialLocation = CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194)
    let region = MKCoordinateRegion(center: initialLocation, latitudinalMeters: 1000, longitudinalMeters: 1000)
    mapView.setRegion(region, animated: true)
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    
    mapView.showsUserLocation = true
    mapView.userTrackingMode = .follow
}