Add button but indicate it's disabled.

resources/lang/en_US/firefly.php

@@ -234,6 +234,7 @@ return [
     // Webhooks
     'webhooks'                             => 'Webhooks',
     'webhooks_breadcrumb'                  => 'Webhooks',
+    'webhooks_menu_disabled' => 'disabled',
     'no_webhook_messages'                  => 'There are no webhook messages',
     'webhook_trigger_STORE_TRANSACTION'    => 'After transaction creation',
     'webhook_trigger_UPDATE_TRANSACTION'   => 'After transaction update',

resources/views/partials/menu-sidebar.twig

@@ -91,6 +91,11 @@
                     <span>{{ 'webhooks'|_ }}</span>
                 </a>
             </li>
+            {% else %}
+                <li class="{{ activeRoutePartial('webhooks') }}">
+                        <span class="fa fa-angle-right fa-fw"></span>
+                        <span>{{ 'webhooks'|_ }} ({{ 'webhooks_menu_disabled'|_ }})</span>
+                </li>
             {% endif %}
         </ul>
     </li>