captcha-module/views/admin_smarty/en/oe_captcha_admin_en_lang.php

<?php

$sLangName = 'English';

$aLang     = [
    'charset'                  => 'UTF-8',
    'SHOP_MODULE_GROUP_main'   => 'General',
    'SHOP_MODULE_oecaptchakey' => 'Captcha Key',
];