View file Web Template Ktpl/package/templates/ktpl/controllers/recaptcha/captcha.tpl.php

<?php $captcha_id = uniqid(); ?>
<fieldset class="captcha_data">
    <legend><?php echo LANG_CAPTCHA_CODE; ?></legend>
    <div class="field recaptcha_wrap">
       <div id="<?php echo $captcha_id; ?>" class="g-recaptcha"></div>
        <script async defer type="text/javascript" src="https://www.google.com/recaptcha/api.js?onload=onload<?php echo $captcha_id; ?>Callback&render=explicit&hl=<?php echo $this->controller->options['lang']; ?>"></script>
        <script type="text/javascript">
            var onload<?php echo $captcha_id; ?>Callback = function() {
                grecaptcha.render('<?php echo $captcha_id; ?>', {
                    sitekey: '<?php echo $this->controller->options['public_key']; ?>',
                    theme: '<?php echo $this->controller->options['theme']; ?>',
                    size: '<?php echo $this->controller->options['size']; ?>'
                });
            };
        </script>
    </div>
</fieldset>