{{ path('entity.node.canonical', {'node':  element['#object'].id}) }}

/**
 * Implements template_preprocess_field__FIELD_NAME().
 */
function MYTHEME_preprocess_field__MYFIELD(&$variables) {

  if ($variables['element']['#entity_type'] === 'node') {
    $node = $variables['element']['#object'];
    $nid = $node->id();
    $variables['myurl'] = Drupal::service('path.alias_manager')->getAliasByPath('/node/' . $nid);
  }
}

{% if myurl %}
   <a href="{{ myurl }}">Kool Keith</a>
{% endif %}