Show an Interstitial Ad.

gistfile1.txt

    private fun showInterstialAd() {
        InterstitialAd.load(
            this,
            "ca-app-pub-3940256099942544/1033173712", //Change this with your own AdUnitID!
            AdRequest.Builder().build(),
            object : InterstitialAdLoadCallback() {
                override fun onAdFailedToLoad(adError: LoadAdError) {
                }

                override fun onAdLoaded(interstitialAd: InterstitialAd) {
                    interstitialAd.show(this@MainActivity)
                }
            }
        )
    }