This should work now

themes/learn2-dark/templates/partials/sidebar.html.twig

@@ -12,7 +12,7 @@
         <li class="dd-item{{ parent_page }}{{ current_page }}" data-nav-id="{{ p.route }}">
             <a href="{{ p.url }}" {% if p.header.class %}class="{{ p.header.class }}"{% endif %}>
                 {#<i class="fa fa-check read-icon"></i>#}
-                {#<span><b>{% if data_level == 0 %}{{ loop.index }}. {% endif %}</b>{{ p.menu }}</span>#}
+                <span><b>{% if data_level == 0 %}{{ loop.index }}. {% endif %}</b>{{ p.menu }}</span>
             </a>
             {% if p.children.count > 0 %}
             <ul>