pdf.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Sales:etc/pdf_file.xsd">
    <totals>
        <total name="subtotal">
            <model>Magento\Tax\Model\Sales\Pdf\Subtotal</model>
        </total>
        <total name="shipping">
            <model>Magento\Tax\Model\Sales\Pdf\Shipping</model>
        </total>
        <total name="grand_total">
            <model>Magento\Tax\Model\Sales\Pdf\Grandtotal</model>
        </total>
        <total name="tax">
            <title translate="true">Tax</title>
            <source_field>tax_amount</source_field>
            <model>Magento\Tax\Model\Sales\Pdf\Tax</model>
            <font_size>7</font_size>
            <display_zero>false</display_zero>
            <sort_order>300</sort_order>
        </total>
    </totals>
</config>