BookStack/resources/views/entities/export-menu.blade.php

<div component="dropdown"
     class="dropdown-container"
     id="export-menu">

    <div refs="dropdown@toggle" class="icon-list-item"
         aria-haspopup="true" aria-expanded="false" aria-label="{{ trans('entities.export') }}" tabindex="0">
        <span>@icon('export')</span>
        <span>{{ trans('entities.export') }}</span>
    </div>

    <ul refs="dropdown@menu" class="wide dropdown-menu" role="menu">
        <li><a href="{{ $entity->getUrl('/export/html') }}" target="_blank" class="label-item"><span>{{ trans('entities.export_html') }}</span><span>.html</span></a></li>
        <li><a href="{{ $entity->getUrl('/export/pdf') }}" target="_blank" class="label-item"><span>{{ trans('entities.export_pdf') }}</span><span>.pdf</span></a></li>
        <li><a href="{{ $entity->getUrl('/export/plaintext') }}" target="_blank" class="label-item"><span>{{ trans('entities.export_text') }}</span><span>.txt</span></a></li>
        <li><a href="{{ $entity->getUrl('/export/markdown') }}" target="_blank" class="label-item"><span>{{ trans('entities.export_md') }}</span><span>.md</span></a></li>
    </ul>

</div>