message error for Django render template

template.html

{% for message in messages %}
  {% if 'success' in message.tags %}
  <p class="alert alert-success" role="alert"><span style="font-weight:bold">{{ message }}</span></p>
  {% else %}
  <p class="alert alert-warning" role="alert"><span style="font-weight:bold">{{ message }}</span></p>
  {% endif %}
{% endfor %}

<script>
  //close alert after 3 seconds
  window.setTimeout(function() {
    $(".alert").fadeTo(500, 0).slideUp(500, function(){
      $(this).remove();
    });
  }, 3000);
</script>

views.py

from django.contrib import messages
from django.contrib.auth.models import User
from django.http import HttpResponseRedirect
from django.shortcuts import render
from django.urls import reverse


def index(request):
    request_message = request.GET.get('message')

    if request_message == 'success':
        msg_success = 'Mensagem de sucesso.'
        messages.success(request, msg_success)
    elif request_message == 'error':
        msg_error = 'Mensagem de erro.'
        messages.error(request, msg_error)

    users = User.objects.all()
    context = {'object_list': users}
    template_name = 'index.html'
    return render(request, template_name, context)


def my_function_to_render_template(request):
    msg_error = 'Mensagem de erro.'
    messages.error(request, msg_error)
    url = 'namespace:name_list'
    return HttpResponseRedirect(reverse(url))