Load translation string

load_translation_string.php

  $locale_storage = Drupal::service('locale.storage');

  $f_name_string_source = $locale_storage->getStrings(['source' => 'First name'], []);
  if (!empty(reset($f_name_string_source))) {
    $f_name_string_source = reset($f_name_string_source);
    $f_name_string = $locale_storage->getTranslations(['language' => 'ro', 'lid' => $f_name_string_source->lid], []);

    if (!empty(reset($f_name_string))) {
      $f_name_string = reset($f_name_string);
      if (!$f_name_string->isNew()) {
        $f_name_string->setString('Prenume')->save();
      }
    }
  }