Error PHP 8, Cart Module

<form action="<?php echo hikashop_completeLink('product&task=updatecart' . $url_itemid, false, true); ?>" method="post" name="<?php echo $form; ?>">
		<div>
			<div>
				<?php
        $k                        = 0;
        $this->cart_product_price = true;
        $group                    = $this->config->get('group_options', 0);
        $cart_id                  = 0;
        $app                      = JFactory::getApplication();
        $productClass             = hikashop_get('class.product');

        $defaultParams = $this->config->get('default_params');

        $this->image = hikashop_get('helper.image');
        $height      = $this->config->get('thumbnail_y');
        $width       = $this->config->get('thumbnail_x');
        foreach ($this->rows as $i => $row) {
            $cart_id = $row->cart_id; // LINE WITH THE ISSUE
            if (empty($row->cart_product_quantity) || @$row->hide == 1)
                continue;
            if ($group && $row->cart_product_option_parent_id)
                continue;
            $productClass->addAlias($row);
?>