You can use below code to set attributes. This will add an attribute to all links in the page. But make sure to add the condition check for your URL.

    /**
     * Implements template_preprocess_menu().
     */
    function THEME_preprocess_menu(&$variables) {
      foreach ($variables['items'] as $item) {
        $item['attributes']->setAttribute('data-target', 'YOUR TARGET NAME');
      }
    }