如何在uitableview admob swift中显示广告？

import GoogleMobileAds

class ViewController: UIViewController, GADBannerViewDelegate {
    var bannerView: GADBannerView!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        bannerView = GADBannerView(adSize: kGADAdSizeBanner)
        bannerView.adUnitID = "YOUR_AD_UNIT_ID"
        bannerView.rootViewController = self
        bannerView.delegate = self
        
        let request = GADRequest()
        bannerView.load(request)
    }
}

override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
    if section == 0 {
        return bannerView
    }
    return nil
}

override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    if section == 0 {
        return bannerView.frame.size.height
    }
    return 0
}

func adViewDidReceiveAd(_ bannerView: GADBannerView) {
    print("Ad received successfully")
}

func adView(_ bannerView: GADBannerView, didFailToReceiveAdWithError error: GADRequestError) {
    print("Ad failed to load: \(error.localizedDescription)")
}

func adViewWillPresentScreen(_ bannerView: GADBannerView) {
    print("Ad will present screen")
}

func adViewWillDismissScreen(_ bannerView: GADBannerView) {
    print("Ad will dismiss screen")
}

func adViewDidDismissScreen(_ bannerView: GADBannerView) {
    print("Ad did dismiss screen")
}

func adViewWillLeaveApplication(_ bannerView: GADBannerView) {
    print("Ad will leave application")
}