SwiftUI AdMob - hide adview on load failed

struct BottomBannerView : View {
    
    @State var isLoaded: Bool = true
    
    var body : some View{
        AdViewBottom(isLoaded: self.$isLoaded)
            .frame(width: 320, height: isLoaded ? 50 : 0)
    }
}

struct AdViewBottom: UIViewRepresentable {
    
    @Binding var isLoaded: Bool
    
    class Coordinator: NSObject, GADBannerViewDelegate {
        func bannerView(_ bannerView: GADBannerView, didFailToReceiveAdWithError error: Error) {
            print("Ad failed to load: \(error.localizedDescription)")
            isLoaded = false // HOW???
        }
    }

    func makeCoordinator() -> Coordinator {
        Coordinator()
    }

    func makeUIView(context: Context) -> GADBannerView {
        let banner = GADBannerView(adSize: GADAdSizeBanner)
        banner.adUnitID = "ca-app-pub-xxx~xxxx"
        // banner.rootViewController = UIApplication.shared.windows.first?.rootViewController // The root view controller is needed to present full screen content.
        banner.delegate = context.coordinator
        banner.load(GADRequest())
        banner.backgroundColor = .black
        return banner
    }

    // SwiftUI calls this method to update the GADBannerView.
    func updateUIView(_ uiView: GADBannerView, context: Context) {
        // In this case, no update is needed.
    }
}

I need to hide the AD when it fails to load, I can't update isLoaded from within the class Coordinator, so how to do this correctly?

You can pass the AdViewBottom instance directly via Coordinator constructor and then toggle the Bool property if needed, something like:

class Coordinator: NSObject, GADBannerViewDelegate {
    let adView: AdViewBottom
    init(_ adView: AdViewBottom) {
        self.adView = adView
    }
    
    func bannerView(_ bannerView: BannerView, didFailToReceiveAdWithError error: Error) {
        adView.isLoaded = false
    }
}

struct AdViewBottom: UIViewRepresentable {
    ...
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
}