Resync WordPress posts' taxonomy translations

polylang-resync-taxonomoy-translations.php

<?php
/**
 * "Resync" WP posts' taxonomy translations.
 *
 * This can either run after the `php` command,
 * followed with CTRL+D x2 (OR x3), or included
 * as a file in `php -a` interactive mode:
 *
 * https://jondavidjohn.com/interactive-wordpress-php-shell/
 */
define('CLI_WP_ROOT', dirname(__FILE__));
// Change this to your WP site url
$_SERVER['HTTP_HOST'] = 'https://www.website-address.com/';

ob_start();
require_once(CLI_WP_ROOT . '/wp-load.php');
require_once(CLI_WP_ROOT . '/wp-admin/includes/admin.php');
ob_end_clean();

$admin_sync   = new PLL_Admin_Sync($polylang);
$src_lang     = 'fi'; // change language as needed
$target_langs = ['en']; // change languages as needed

$posts = get_posts([
  'posts_per_page' => PHP_INT_MAX,
  'lang' => $src_lang,
]);

foreach ($posts as $a_post) {
  foreach ($target_langs as $target_lang) {
    $trans_post_ID = pll_get_post($a_post->ID, $target_lang);

    if ($trans_post_ID) {
      $admin_sync->copy_taxonomies($a_post->ID, $trans_post_ID, $target_lang);
    }
  }
}