$executionStartTime = microtime(true);

set_time_limit(0);

$orderby = 'parent';
$order = 'asc';
$hide_empty = false ;
$cat_args = array(
    'orderby'    => $orderby,
    'order'      => $order,
    'hide_empty' => $hide_empty,
);

$product_categories = get_terms( 'product_cat', $cat_args );

/*
    * PLL()->duplicate->duplicate_term( $tr_term, $term, $lang );
    * $tr_term: always set it to false (or something empty).
    * $term: The term_id of the term to duplicate
    * $lang: The language code of the new term that you want ot create.
    */

foreach ($product_categories as $category) {

        PLL()->duplicate->duplicate_term( false, $category->term_id, en );
        PLL()->duplicate->duplicate_term( false, $category->term_id, de );
        PLL()->duplicate->duplicate_term( false, $category->term_id, fr );



    /*
    echo '<ul>';
    echo '<li>';
    echo '<a href="'.get_term_link($category).'" >';
    echo $category->name;
    echo '</a>';
    echo '  parent id: ' . $category->parent;
    echo '  term id: ' . $category->term_id;
    echo '</li>';
    echo '</ul>';
    */

}

$executionEndTime = microtime(true);
  $seconds = $executionEndTime - $executionStartTime;
  echo 'Done! execution time ' . date("i:s:v",$seconds);