You can use
path('entity.node.canonical', {'node': dd.nid})
path('entity.node.canonical', {'node': dd.nid})
in the template file.
So theThe markup in the template file would look like this.
<li><a href="{{path('entity.node.canonical', {'node': dd.nid})}}">{{ 'About Us'|t }}</a></li>
ThoughI haven't tried it, but thisit should work.
Source - http://www.singhalamit.com/topic/drupal-8/how-get-alias-node-twig-file-drupal-8