code: def post_registration_redirect(self, request, user):
          
          next_url = "/registration/register/complete/"
          if "next" in request.GET or "next" in request.POST:
              next_url = request.GET.get("next", None) or request.POST.get("next", None) or "/"
              
          return (next_url, (), {})
docs: After registration, redirect to the home page or supplied "next"
          query string or hidden field value.