netbox-community-netbox/netbox/templates/inc/modal.html

<div class="modal fade" id="{{ name }}_modal" tabindex="-1" role="dialog">
    <div class="modal-dialog modal-lg" role="document">
        <div class="modal-content">
            {% if title %}
                <div class="modal-header">
                    <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
                    <h4 class="modal-title">{{ title }}</h4>
                </div>
            {% endif %}
            <div class="modal-body">
                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
                {{ content }}
            </div>
        </div>
    </div>
</div>