XZing with xamarin forms

Hello I'm trying to implement barcode reading in my Xamarin.Forms app according to the documentation.

link , but when I try to run the code below

private async void ExecuteBuscaInventarioCommand()
{
    try
    {
        var scanner = new ZXing.Mobile.MobileBarcodeScanner();
        var result = await scanner.Scan();

        if (result != null)
            Codigo = result.Text;
    }
    catch (Exception ex)
    {
        await App.Current.MainPage.DisplayAlert("Ops!", ex.Message, "Ok");
    }
}

I get the message System.NotSupportedException: Use the platform specific implementation instead!

In the documentation says for me to add an android support component but the link that is broken ...

In the constructor I put this

MobileBarcodeScanner.Initialize(Application);

but Initialize is not recognized.

Can someone give me a light?