Isn’t Admob running at Unity?

Question

I imported the plugin as per admob’s website , plugin link

I used the following code for testing

using System;
using UnityEngine;
using GoogleMobileAds;
using GoogleMobileAds.Api;

public class GoogleMobileAdsDemoHandler : IInAppPurchaseHandler
{
    private readonly string[] validSkus = { "android.test.purchased" };

    //Will only be sent on a success.
    public void OnInAppPurchaseFinished(IInAppPurchaseResult result)
    {
        result.FinishPurchase();
        GoogleMobileAdsDemoScript.OutputMessage = "Purchase Succeeded! Credit user here.";
    }

    //Check SKU against valid SKUs.
    public bool IsValidPurchase(string sku)
    {
        foreach(string validSku in validSkus) {
            if (sku == validSku) {
                return true;
            }
        }
        return false;
    }

    //Return the app's public key.
    public string AndroidPublicKey
    {
        //In a real app, return public key instead of null.
        get { return null; }
    }
}

// Example script showing how to invoke the Google Mobile Ads Unity plugin.
public class GoogleMobileAdsDemoScript : MonoBehaviour
{

    private BannerView bannerView;
    private InterstitialAd interstitial;
    private static string outputMessage = "";

    public static string OutputMessage
    {
        set { outputMessage = value; }
    }

    void OnGUI()
    {
        // Puts some basic buttons onto the screen.
        GUI.skin.button.fontSize = (int) (0.05f * Screen.height);
        GUI.skin.label.fontSize = (int) (0.025f * Screen.height);

        Rect requestBannerRect = new Rect(0.1f * Screen.width, 0.05f * Screen.height,
                                   0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(requestBannerRect, "Request Banner"))
        {
            RequestBanner();
        }

        Rect showBannerRect = new Rect(0.1f * Screen.width, 0.175f * Screen.height,
                                       0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(showBannerRect, "Show Banner"))
        {
            bannerView.Show();
        }

        Rect hideBannerRect = new Rect(0.1f * Screen.width, 0.3f * Screen.height,
                                       0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(hideBannerRect, "Hide Banner"))
        {
            bannerView.Hide();
        }

        Rect destroyBannerRect = new Rect(0.1f * Screen.width, 0.425f * Screen.height,
                                          0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(destroyBannerRect, "Destroy Banner"))
        {
            bannerView.Destroy();
        }

        Rect requestInterstitialRect = new Rect(0.1f * Screen.width, 0.55f * Screen.height,
                                                0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(requestInterstitialRect, "Request Interstitial"))
        {
            RequestInterstitial();
        }

        Rect showInterstitialRect = new Rect(0.1f * Screen.width, 0.675f * Screen.height,
                                             0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(showInterstitialRect, "Show Interstitial"))
        {
            ShowInterstitial();
        }

        Rect destroyInterstitialRect = new Rect(0.1f * Screen.width, 0.8f * Screen.height,
                                                0.8f * Screen.width, 0.1f * Screen.height);
        if (GUI.Button(destroyInterstitialRect, "Destroy Interstitial"))
        {
            interstitial.Destroy();
        }

        Rect textOutputRect = new Rect(0.1f * Screen.width, 0.925f * Screen.height,
                                   0.8f * Screen.width, 0.05f * Screen.height);
        GUI.Label(textOutputRect, outputMessage);
    }

    private void RequestBanner()
    {
        #if UNITY_EDITOR
            string adUnitId = "unused";
        #elif UNITY_ANDROID
            string adUnitId = "INSERT_ANDROID_BANNER_AD_UNIT_ID_HERE";
        #elif UNITY_IPHONE
            string adUnitId = "INSERT_IOS_BANNER_AD_UNIT_ID_HERE";
        #else
            string adUnitId = "unexpected_platform";
        #endif

        // Create a 320x50 banner at the top of the screen.
        bannerView = new BannerView(adUnitId, AdSize.SmartBanner, AdPosition.Top);
        // Register for ad events.
        bannerView.AdLoaded += HandleAdLoaded;
        bannerView.AdFailedToLoad += HandleAdFailedToLoad;
        bannerView.AdOpened += HandleAdOpened;
        bannerView.AdClosing += HandleAdClosing;
        bannerView.AdClosed += HandleAdClosed;
        bannerView.AdLeftApplication += HandleAdLeftApplication;
        // Load a banner ad.
        bannerView.LoadAd(createAdRequest());
    }

    private void RequestInterstitial()
    {
        #if UNITY_EDITOR
            string adUnitId = "unused";
        #elif UNITY_ANDROID
            string adUnitId = "INSERT_ANDROID_INTERSTITIAL_AD_UNIT_ID_HERE";
        #elif UNITY_IPHONE
            string adUnitId = "INSERT_IOS_INTERSTITIAL_AD_UNIT_ID_HERE";
        #else
            string adUnitId = "unexpected_platform";
        #endif

        // Create an interstitial.
        interstitial = new InterstitialAd(adUnitId);
        // Register for ad events.
        interstitial.AdLoaded += HandleInterstitialLoaded;
        interstitial.AdFailedToLoad += HandleInterstitialFailedToLoad;
        interstitial.AdOpened += HandleInterstitialOpened;
        interstitial.AdClosing += HandleInterstitialClosing;
        interstitial.AdClosed += HandleInterstitialClosed;
        interstitial.AdLeftApplication += HandleInterstitialLeftApplication;
        GoogleMobileAdsDemoHandler handler = new GoogleMobileAdsDemoHandler();
        interstitial.SetInAppPurchaseHandler(handler);
        // Load an interstitial ad.
        interstitial.LoadAd(createAdRequest());
    }

    // Returns an ad request with custom ad targeting.
    private AdRequest createAdRequest()
    {
        return new AdRequest.Builder()
                .AddTestDevice(AdRequest.TestDeviceSimulator)
                .AddTestDevice("0123456789ABCDEF0123456789ABCDEF")
                .AddKeyword("game")
                .SetGender(Gender.Male)
                .SetBirthday(new DateTime(1985, 1, 1))
                .TagForChildDirectedTreatment(false)
                .AddExtra("color_bg", "9B30FF")
                .Build();

    }

    private void ShowInterstitial()
    {
        if (interstitial.IsLoaded())
        {
            interstitial.Show();
        }
        else
        {
            print("Interstitial is not ready yet.");
        }
    }

    #region Banner callback handlers

    public void HandleAdLoaded(object sender, EventArgs args)
    {
        print("HandleAdLoaded event received.");
    }

    public void HandleAdFailedToLoad(object sender, AdFailedToLoadEventArgs args)
    {
        print("HandleFailedToReceiveAd event received with message: " + args.Message);
    }

    public void HandleAdOpened(object sender, EventArgs args)
    {
        print("HandleAdOpened event received");
    }

    void HandleAdClosing(object sender, EventArgs args)
    {
        print("HandleAdClosing event received");
    }

    public void HandleAdClosed(object sender, EventArgs args)
    {
        print("HandleAdClosed event received");
    }

    public void HandleAdLeftApplication(object sender, EventArgs args)
    {
        print("HandleAdLeftApplication event received");
    }

    #endregion

    #region Interstitial callback handlers

    public void HandleInterstitialLoaded(object sender, EventArgs args)
    {
        print("HandleInterstitialLoaded event received.");
    }

    public void HandleInterstitialFailedToLoad(object sender, AdFailedToLoadEventArgs args)
    {
        print("HandleInterstitialFailedToLoad event received with message: " + args.Message);
    }

    public void HandleInterstitialOpened(object sender, EventArgs args)
    {
        print("HandleInterstitialOpened event received");
    }

    void HandleInterstitialClosing(object sender, EventArgs args)
    {
        print("HandleInterstitialClosing event received");
    }

    public void HandleInterstitialClosed(object sender, EventArgs args)
    {
        print("HandleInterstitialClosed event received");
    }

    public void HandleInterstitialLeftApplication(object sender, EventArgs args)
    {
        print("HandleInterstitialLeftApplication event received");
    }

    #endregion
}

It simply does not work in the emulator to request the advertisement it closes already on the physical device does not close but nothing happens.

emulator looks like this