Hi Mostafa,
When you request the first ad (either Interstitial or banner or rewardVideo) you can find a HASH string about which you can add in code to get Test Ads from Google on particular Device. clicking on Test ad will not break any rules of AdMob.
here is sample code how to use HASH string to set Devices as Test Device
private AdRequest CreateAdRequest() {
MyDebug.Log(string.Format("GMAS::CreateAdRequest"));
// Google Test Ad Unit ID
// ca-app-pub-3940256099942544/1033173712
return new AdRequest.Builder()
.AddTestDevice(AdRequest.TestDeviceSimulator)
//
// .AddTestDevice("iOS Device 1 Hash Key from XCode Log")
// .AddTestDevice("iOS Device 2 Hash Key from XCode Log")
// .AddTestDevice("Android Device 1 Hash Key from Android Monitor Log")
// .AddTestDevice("Android Device 2 Hash Key from Android Monitor Log")
// and so on other Decice if you have
//
//.AddExtra("color_bg", "9B30FF")
//.AddKeyword("Unity3D")
//.AddKeyword(GUtility.Me.APPNAME)
//.SetGender(Gender.Male)
//.SetBirthday(new DateTime(1985, 1, 1))
//.TagForChildDirectedTreatment(false)
.Build();
}
Or There are be a method in AdMob plugin by VNTIS where you can add those hash key to set devices as test deice. which will provide you test ads