netbox/netbox/templates/utilities/render_errors.html

{% load form_helpers %}

{% if form.errors or form.non_field_errors %}
<div class="alert alert-danger mt-3" role="alert">
  <h4 class="alert-heading">Errors</h4>
  <hr />
  <div class="ps-2">
    {% if form.errors %}
    {% for field_name, errors in form.errors.items %}
    {% with field=form|getfield:field_name %}
    <strong>{{ field.label }}</strong>
        <ul>
        {% for error in errors %}
            <li>{{ error }}</li>
        {% endfor %}
        </ul>
    {% endwith %}
    {% endfor %}
    {% endif %}
    {% if form.non_field_errors %}
    <hr />
    {{ form.non_field_errors }}
    {% endif %}
  </div>
</div>
{% endif %}