Get android WiFi Mac address

Hello I’m trying to access to the mac of my android device but I can’t.
I have tries los of methods like this:

function GetMacAddress(){
    var macAdress = "";
    var nics : NetworkInterface[] = NetworkInterface.GetAllNetworkInterfaces();
    var i = 0;
    for (var adapter: NetworkInterface in nics){
        var address: PhysicalAddress = adapter.GetPhysicalAddress();
        if(address.ToString() != ""){
            macAdress = address.ToString();
            return macAdress;
        }
    }
    return 0;
}

And this:

  AndroidJavaObject mWiFiManager;

 

   string ReturnMacAddress()

   {

      string macAddr = "";

      if (mWiFiManager == null)

      {

         using (AndroidJavaObject activity = new AndroidJavaClass("com.unity3d.player.UnityPlayer").GetStatic<AndroidJavaObject>("currentActivity"))

         {

            mWiFiManager = activity.Call<AndroidJavaObject>("getSystemService","wifi");

         }

      }

      macAddr = mWiFiManager.Call<AndroidJavaObject>("getConnectionInfo").Call<string>("getMacAddress"

      return macAddr;

  }

Any of this ways returns me anything on my android device, I’m desperated, please I need help.

Use option with java and add to the manifest
``
and it will work.