Google Admob delegate method bannerViewDidReceiveAd not called

I wanted to prepare helper class for Admob to manage Banner ads. I set the delegate But bannerViewDidReceiveAd method not called. Do you know what could be issue?

protocol BannerAdsManagerProtocol: AnyObject {
func bannerDidReceiveAd(bannerView: GADBannerView)
}

class BannerAdsManager: NSObject {

var bannerView: GADBannerView!

weak var delegate: BannerAdsManagerProtocol?
var rootViewController: UIViewController

init(rootViewController: UIViewController, delegate: BannerAdsManagerProtocol?) {
    self.rootViewController = rootViewController
    self.delegate = delegate
}


func loadAd(with unitId: String, adSize: GADAdSize) {
    self.bannerView = GADBannerView(adSize: adSize)
    self.bannerView.adUnitID = unitId
    self.bannerView.rootViewController = rootViewController
    self.bannerView.delegate = self
    let request = GADRequest()
    self.bannerView.load(request)
}
}

extension BannerAdsManager: GADBannerViewDelegate {

func bannerViewDidReceiveAd(_ bannerView: GADBannerView) {
    print(#function)
    delegate?.bannerDidReceiveAd(bannerView: bannerView)
}


func bannerView(_ bannerView: GADBannerView, didFailToReceiveAdWithError error: Error) {
    print(error.localizedDescription)
}
}`

This is how I use to receive bannerView in my ViewController.

override func viewDidLoad() {
        super.viewDidLoad()
    
        let bannerAdsManager = BannerAdsManager(rootViewController: self,
                                                delegate: self)
        bannerAdsManager.loadAd(with: adId, adSize: GADAdSizeLargeBanner)
        )
  }
extension ListViewController: BannerAdsManagerProtocol {
    func bannerDidReceiveAd(bannerView: GADBannerView) {
        addBannerViewToView(bannerView, attritube: .bottom)
    }
}

BannerAdsManager gets deallocated as soon as viewDidLoad has finished. You need to store it somewhere outside of the function.

For example, change your viewcontroller to this:

class ListViewController: UIViewController {
    
    var bannerAdsManager: BannerAdsManager!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        bannerAdsManager = BannerAdsManager(rootViewController: self,
                                            delegate: self)
        bannerAdsManager.loadAd(with: adId, adSize: GADAdSizeLargeBanner)
    }
}

extension ListViewController: BannerAdsManagerProtocol {
    func bannerDidReceiveAd(bannerView: GADBannerView) {
        addBannerViewToView(bannerView, attritube: .bottom)
    }
}

(I assumed your viewcontroller is named "ListViewController" and you wanted the extension to conform to your protocol.)

There may be more issues, that's all I could get from the given code.