以下のようになっていました。

<!-- 出荷済にする確認モーダル -->
<div class="modal fade" id="sentUpdateModal" tabindex="-1" role="dialog" aria-labelledby="sentUpdateModal" aria-hidden="true" data-keyboard="false" data-backdrop="static">
<div class="modal-dialog modal-lg" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title font-weight-bold"><!--confirmationModal_js.twig--></h5>
<button class="close" type="button" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
</div>
<div class="modal-body">
<p class="modal-message"></p>
<ul id="bulkErrors"></ul>
<div id="bulk-options">
<div class="font-weight-bold mb-2 notificationMail">{{ 'admin.order.to_shipped__confirm_send_mail'|trans }}</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="checkbox" id="notificationMail">
<label class="form-check-label notificationMail">
{{ 'admin.order.to_shipped__confirm_send_mail_in_same_time'|trans }}
</label>
</div>
<div>
<div class="d-inline-block" data-toggle="collapse" href="#viewEmail" aria-expanded="false" aria-controls="viewEmail"><a><i class="fa fa-plus-square-o font-weight-bold mr-1"></i><span class="font-weight-bold">{{ 'admin.order.bulk_action__confirm_view_mail_body'|trans }}</span></a></div>
<div class="collapse bg-light p-4 ec-collapse bg-ec-formGray" id="viewEmail" style="word-wrap: break-word; word-break:break-all">
<pre></pre>
</div>
</div>
</div>
<div class="progress" style="display: none">
<div class="progress-bar progress-bar-striped progress-bar-animated" role="progressbar" style="width: 0%" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100"></div>
</div>
</div>
<div class="modal-footer">
<button class="btn btn-ec-sub" type="button" data-dismiss="modal">{{ 'admin.common.cancel'|trans }}</button>
<button id="bulkChange" class="btn btn-ec-conversion" type="button"><!--confirmationModal_js.twig--></button>
<button id="bulkChangeComplete" class="btn btn-ec-regular" style="display: none" type="button">{{ 'admin.common.close'|trans }}</button>
</div>
</div>
</div>
</div>