Why my interstitial ads is not showing in andorid kotlin

Question

**I tried it lots of times but I failed. I am new to Android development. Is my code correct? Please help me. I created a class for load the ads loading work : **

class InterstitialAds {


    var mInterstitialAd: InterstitialAd? = null


     fun interAds(context: Context){

        MobileAds.initialize(context)


        var adRequest = AdRequest.Builder().build()

        InterstitialAd.load(context,"ca-app-pub-3940256099942544/1033173712", adRequest, object : InterstitialAdLoadCallback() {

            override fun onAdFailedToLoad(adError: LoadAdError) {
                adError?.toString()?.let { Log.d(ContentValues.TAG, it) }
                mInterstitialAd = null
            }

            override fun onAdLoaded(interstitialAd: InterstitialAd) {
                mInterstitialAd = interstitialAd

            }
        })
    }
}

** In Adapter : **

holder.thumbnail.setOnClickListener {


            val interstitialAds = InterstitialAds()
            interstitialAds.interAds(context)


            if (interstitialAds.mInterstitialAd != null) {
                interstitialAds.mInterstitialAd!!.show(context as Activity)
                interstitialAds.mInterstitialAd!!.fullScreenContentCallback =
                    object : FullScreenContentCallback() {

                        override fun onAdDismissedFullScreenContent() {
                            // Called when ad is dismissed.
                            interstitialAds.mInterstitialAd = null
                            interstitialAds.interAds(context)
                            progressBar.visibility = View.VISIBLE
                            webView.visibility = View.VISIBLE
                            thumnail.visibility = View.GONE

                            val webSettings: WebSettings = webView.settings
                            webSettings.javaScriptEnabled = true


                            webView.webViewClient = object : WebViewClient() {
                                override fun onPageFinished(view: WebView?, url: String?) {
    
                                    progressBar.visibility = View.GONE
                                    fullButton.visibility = View.VISIBLE

                                }
                            }

                            webView.loadData(item.videoEmbed!!, "text/html", "utf-8")


                        }

                    }
                
            }

**Can anyone help me to solve this issue. Is my code correct? Please help me. I created a class for load the ads loading work **

Answer 1

If your app is in production, Use RequestConfiguration.Builder().setTestDeviceIds(Arrays.asList("455FDC94B1F5B4415BD853EEB4FFCDB0"))

before MobileAds.initialize(context)

If you do not know TestDeviceId then search safeDK Device ID in logcat.

If that does not work then change your package name for testing purposes. And change it back before releasing a new update