vij/partials/formsubscript.php

<?php 
session_start();
$num1 = rand(1, 10);
$num2 = rand(1, 10);
$_SESSION['captcha'] = $num1 + $num2;
?>

<div id="subscript_box">    
    <div id="convert"></div>   
    <div class="right_title"><?=vij_lang('email_title', LANG_VERSION);?></div>
    <div id="subscript-mail">
        <form class="form-right" id="form-right" action="https://vetandlife.ru/subscript" method="post">
            <input сlass="frm_mail" type="email" required name="email" placeholder="<?=vij_lang('your_mail', LANG_VERSION);?>">
            <?php wp_nonce_field('subscription_form_nonce', 'subscription_nonce'); ?>
            <input type="text" class="mytext" name="mytext" placeholder="Дополнительный текст">
            <button class="frm_submit"><?=vij_lang('email_btn', LANG_VERSION);?></button> 
        </form>
    </div>
</div>