locale_form_system_file_system_settings_alter

locale_form_system_file_system_settings_alter(&$form, FormStateInterface $form_state)

function locale_form_system_file_system_settings_alter(&$form, FormStateInterface $form_state) {
  $form['translation_path'] = array(
    '#type' => 'textfield',
    '#title' => t('Interface translations directory'),
    '#default_value' => \Drupal::configFactory()->getEditable('locale.settings')->get('translation.path'),
    '#maxlength' => 255,
    '#description' => t('A local file system path where interface translation files will be stored.'),
    '#required' => TRUE,
    '#after_build' => array('system_check_directory'),
    '#weight' => 10,
  );
  if ($form['file_default_scheme']) {
    $form['file_default_scheme']['#weight'] = 20;
  }
  $form['#submit'][] = 'locale_system_file_system_settings_submit';
}