Interstitial ads pops up after every X seconds - swift

Question

can anyone please help me with this. How to show interstitial ads pop out after every x seconds and the ad will run only for few seconds and go back to the Main Screen.
Currently I am using this:
This is the Banner Ad:
import GoogleMobileAds
import SwiftUI
import UIKit
struct GADBannerViewController: UIViewControllerRepresentable {
func makeUIViewController(context: Context) -> UIViewController {
let adSize = GADAdSizeFromCGSize(CGSize(width: 320, height: 100))
let view = GADBannerView(adSize: adSize)
let viewController = UIViewController()
view.adUnitID = "ca-app-pub-3940256099942544/2934735716"
view.rootViewController = viewController
viewController.view.addSubview(view)
viewController.view.frame = CGRect(origin: .zero, size: adSize.size)
view.load(GADRequest())
return viewController
}
func updateUIViewController(_ uiViewController: UIViewController, context: Context) {}
}
This is the Interstitial Ad:
import GoogleMobileAds
import SwiftUI
import UIKit
final class Interstitial:NSObject, GADFullScreenContentDelegate {
var interstitial:GADInterstitialAd?
override init() {
super.init()
self.loadInterstitial()
}
func loadInterstitial(){
let request = GADRequest()
GADInterstitialAd.load(withAdUnitID:"ca-app-pub-3940256099942544/4411468910",
request: request,
completionHandler: { [self] ad, error in
if let error = error {
print("Failed to load interstitial ad with error: \(error.localizedDescription)")
return
}
interstitial = ad
interstitial?.fullScreenContentDelegate = self
})
}
func showAd(){
if self.interstitial != nil {
let root = UIApplication.shared.windows.first?.rootViewController
self.interstitial?.present(fromRootViewController: root!)
}
else{
print("Not Ready")
}
}
func adDidDismissFullScreenContent(_ ad: GADFullScreenPresentingAd) {
print("Ad did dismiss full screen content.")
self.loadInterstitial()
}
}
And this is how I am currently implementing in my View.
import SwiftUI
import GoogleMobileAds
struct AdvertView: View {
private var fullScreenAd: Interstitial?
init() {
fullScreenAd = Interstitial()
}
var body: some View {
let adSize = GADAdSizeFromCGSize(CGSize(width: 320, height: 100))
NavigationView {
Form {
Button("test", action: {
self.fullScreenAd?.showAd()
})
//Banner
HStack {
Spacer()
GADBannerViewController()
.frame(width: adSize.size.width, height: adSize.size.height)
Spacer()
}
}
.navigationBarTitle("Ad Test")
}
}
}
So, when I press the Test Button, the ad changes to Interstitial ad.
I want to appear the ads both Banner and Interstitial on different screens after certain timings without using the buttons. Can anyone please help me with this?