nginx-proxy-manager/frontend/js/app/help/main.ejs

<div class="modal-content">
    <div class="modal-header">
        <h5 class="modal-title"><%- title %></h5>
        <button type="button" class="close cancel" aria-label="Close" data-dismiss="modal">&nbsp;</button>
    </div>
    <div class="modal-body">
        <%= content %>
    </div>
    <div class="modal-footer">
        <button type="button" class="btn btn-secondary cancel" data-dismiss="modal"><%- i18n('str', 'close') %></button>
    </div>
</div>