Navigate back to previous page.

Hi Guys,

I'm currenly experimenting with Xamarin forms, I'm having trouble navigating from webView back to previous menu.

     public void ButtonName(object sender, EventArgs args)
     {
        var browser = new WebView();
        browser.Source = "websiteURL";
        Content = browser;
}

I have this for my button which loads a website, but once on this page I cannot nav back to the menu. I tried adding a button on the navbar like so;

ToolbarItems.Add(new ToolbarItem
            {
                Name = "Done",
                Command = new Command(() => Navigation.PopAsync()),
            });

But have had no luck. I'm extremely new to Coding in C# so some tips would be great!