<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">

    <body>        
        <referenceContainer name="order_totals">
            <block class="Slimcd\Payment\Block\Sales\Order\Surcharge" name="surcharge"/>
        </referenceContainer>
    </body>
</page>