rivet-1.0.x-dev/templates/block/block--region-sidebar--menu-block.html.twig

{% if content %}
{{ attach_library('rivet/rvt-c-sidenav')}}
<nav{{attributes.addClass('rvt-sidenav')|without('id')}} aria-labelledby="sidenav-label" data-rvt-sidenav>
  {{ title_prefix }}
  {% if label %}
    <span{{title_attributes.addClass('rvt-sidenav__label')}} id="sidenav-label">
    {{ label }}
    </span>
  {% endif %}
  {{ content }}
  {{ title_suffix }}
</nav>
{% endif %}