templates/admin/auth/user/add_form.html

{% extends "admin/change_form.html" %}
{% load i18n %}

{% block form_top %}
  {% if not is_popup %}
    <p>{% translate 'First, enter a username and password. Then, you’ll be able to edit more user options.' %}</p>
  {% else %}
    <p>{% translate "Enter a username and password." %}</p>
  {% endif %}
{% endblock %}