NotificationArea component in custom template

Hi !

I am trying to use the notification component in a custom template, but it is not working. If someone is using it it would be of great help some idea how to incorporate it. I tried to add like a normal component and like a root but I could notget it.

import panel as pn
import holoviews as hv

template = """
{% extends base %}

<!-- goes in body -->
{% block postamble %}
<link rel="stylesheet" href="">
{% endblock %}

<!-- goes in body -->
{% block contents %}
{{ app_title }}
<p>This is a Panel app with a custom template allowing us to compose multiple Panel objects into a single HTML document.</p>
<div class="container">
  <div class="row">
    <div class="col-sm">
      {{ embed(roots.A) }}
    <div class="col-sm">
      {{ embed(roots.B) }}
{% endblock %}

tmpl = pn.Template(template)

tmpl.add_variable('app_title', '<h1>Custom Template App</h1>')

tmpl.add_panel('A', hv.Curve([1, 2, 3]))
tmpl.add_panel('B', hv.Curve([1, 2, 3]))

pn.state.notifications.error('This is an error notification.', duration=0)