code: def show_url(context, **kwargs):
      
      if len(kwargs) != 2:
          raise TemplateSyntaxError(_('"show_url" tag takes exactly two keyword arguments.'))
      request = context['request']
      current_site = get_current_site(request)
      url = add_domain(current_site.domain, kwargs['url'])
      return re.sub(r'https?:\/\/', '%s://' % kwargs['protocol'], url)
docs: Return the show feed URL with different protocol.