add app user management allauth

templates/404.html

@@ -0,0 +1,10 @@
+{% extends 'layouts/blank.html' %} {% block content %}
+
+<div class="container text-center py-5">
+  <h1 class="display-1">Page not found</h1>
+  <p class="my-4 text-muted">
+    Error 404: This page doesn't exist or is unavailable
+  </p>
+</div>
+
+{% endblock %}