Scanning Wifi from PCL project using Dependency Service

Hello!
I need to scan the wifi programatically and return a list of all SSID's I get. I've read about it and concluded I can't make it on iOS in a way I can publish the App on the Apple Store(ref).
So, I decided to at least implement it for Android Users, I'm trying to implement via Dependency Service but I'm doing it wrong, here is what I'm doing:

This is the Wifi.cs class in the Android project:

using AirSenseApp.Services;
using Android.Content;
using Android.Net.Wifi;
using System.Collections.Generic;

[assembly: Xamarin.Forms.Dependency(typeof(AirSenseApp.Droid.Classes.Wifi))]
namespace AirSenseApp.Droid.Classes
{
    public class Wifi:IWifi
    {
        private Context context = null;
        private static WifiManager wifi;
        private WifiReceiver wifiReceiver;
        public static List<string> WiFiNetworks;

        public Wifi(Context ctx)
        {
            this.context = ctx;
        }

        public void GetWifiNetworks()
        {
            WiFiNetworks = new List<string>();

            // Get a handle to the Wifi
            wifi = (WifiManager)context.GetSystemService(Context.WifiService);

            // Start a scan and register the Broadcast receiver to get the list of Wifi Networks
            wifiReceiver = new WifiReceiver();
            context.RegisterReceiver(wifiReceiver, new IntentFilter(WifiManager.ScanResultsAvailableAction));
            wifi.StartScan();
        }

        public class WifiReceiver:BroadcastReceiver
        {
            public override void OnReceive(Context context, Intent intent)
            {
                IList<ScanResult> scanwifinetworks = wifi.ScanResults;
                foreach(ScanResult wifinetwork in scanwifinetworks)
                {
                    WiFiNetworks.Add(wifinetwork.Ssid);
                }
            }
        }
    }
}

This is my Interface that I'm trying to implement on the PCL project:

using System;
using System.Collections.Generic;
using System.Text;

namespace AirSenseApp.Services
{
    public interface IWifi
    {
        void GetWifiNetworks();

    }
}

Is this the correct way to implement it? I tried to put it in my ViewModel this way:

public class CreateDeviceViewModel:INotifyPropertyChanged
{
    private readonly IWifi _wifiService;
    public CreateDeviceViewModel()
    {
        this._wifiService = DependencyService.Get<IWifi>();
    }
    public ScanWifiButtonPressed()
    {
        _wifiService.GetWifiNetworks();
    }
}

But I receive this error:
[0:] System.MissingMethodException: Default constructor not found for type AirSenseApp.Droid.Classes.Wifi

This means I'm not implementing the Wifi.cs in the Android project in the correct way or the problem is in the Interface?