checkout.php

См. документацию.

<?php
use Bitrix\Main\Localization\Loc;
 
Loc::loadMessages(__FILE__);
?>
<div class="mb-4" >
    <p><?= Loc::getMessage('SALE_HANDLERS_PAY_SYSTEM_TEMPLATE_CHECKOUT_WOOPPAY_DESCRIPTION'); ?></p>
    <p><?= Loc::getMessage(
        'SALE_HANDLERS_PAY_SYSTEM_TEMPLATE_CHECKOUT_WOOPPAY_SUM',
        [
            '#SUM#' => SaleFormatCurrency($params['sum'], $params['currency']),
        ]
    ); ?></p>
    <div class="d-flex align-items-center mb-3">
        <div class="col-auto pl-0">
            <a class="btn btn-lg btn-success" style="border-radius: 32px;" href="<?= $params['url']; ?>"><?= Loc::getMessage('SALE_HANDLERS_PAY_SYSTEM_TEMPLATE_CHECKOUT_WOOPPAY_BUTTON_PAID'); ?></a>
        </div>
        <div class="col pr-0"><?= Loc::getMessage('SALE_HANDLERS_PAY_SYSTEM_TEMPLATE_CHECKOUT_WOOPPAY_REDIRECT_MESS'); ?></div>
    </div>
    <div class="alert alert-info"><?= Loc::getMessage('SALE_HANDLERS_PAY_SYSTEM_TEMPLATE_CHECKOUT_WOOPPAY_WARNING_RETURN'); ?></div>
</div>