magento-test/app/code/Magento/Dhl/view/adminhtml/templates/unitofmeasure.phtml

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
/**
 * @var \Magento\Dhl\Block\Adminhtml\Unitofmeasure $block
 * @var \Magento\Framework\View\Helper\SecureHtmlRenderer $secureRenderer
 */
?>

<?php $scriptString = <<<script
    //<![CDATA[
    require(["prototype"], function(){
        function changeDimensions() {
            var dimensionUnit = "({$block->escapeHtml($block->getInch())})";
            var dhlUnitOfMeasureNote = "{$block->escapeHtml($block->getDivideOrderWeightNoteLbp())}";
            if ($("carriers_dhl_unit_of_measure").value == "K") {
                dimensionUnit = "({$block->escapeHtml($block->getCm())})";
                dhlUnitOfMeasureNote = "{$block->escapeHtml($block->getDivideOrderWeightNoteKg())}";
            }
            \$$('[for="carriers_dhl_height"]')[0].innerHTML = "{$block->escapeHtml($block->getHeight())} " +
             dimensionUnit;
            \$$('[for="carriers_dhl_depth"]')[0].innerHTML = "{$block->escapeHtml($block->getDepth())} " +
             dimensionUnit;
            \$$('[for="carriers_dhl_width"]')[0].innerHTML = "{$block->escapeHtml($block->getWidth())} " +
             dimensionUnit;

            $("carriers_dhl_divide_order_weight").next().down().innerHTML = dhlUnitOfMeasureNote;
        }
        window.changeDimensions = changeDimensions;
        document.observe("dom:loaded", function() {
            $("carriers_dhl_unit_of_measure").observe("change", changeDimensions);
            changeDimensions();
        });
    });
    //]]>
script;
?>
<?= /* @noEscape */ $secureRenderer->renderTag('script', [], $scriptString, false) ?>