newsupernova/vendor/magento/module-theme/view/adminhtml/templates/tabs/fieldset/js.phtml

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

// @codingStandardsIgnoreFile
?>
<?php /** @var $block \Magento\Backend\Block\Widget\Form\Renderer\Fieldset */ ?>

<div id="js-file-uploader" class="uploader">
</div>
<script id="js-file-uploader-template" type="text/x-magento-template"> 
    <div id="<%- data.id %>" class="file-row">
        <span class="file-info"><%- data.name %> (<%- data.size %>)</span>
        <div class="progressbar-container">
            <div class="progressbar upload-progress" style="width: 0%;"></div>
        </div>
        <div class="clear"></div>
    </div>
</script>
<script id="js-uploaded-file-template" type="text/x-magento-template">
    <input class="up" type="button" value="">
    <input class="down" type="button" value="">
    <input type="hidden" name="js_order[<%- data.id %>]" value="1">

    <div class="js-file">
        <%- data.name %>
        <div class="remove-js">
            <input
                type="checkbox"
                id="remove_js_files_<%- data.id %>"
                name="js_removed_files[]"
                value="<%- data.id %>" />
            <label for="remove_js_files_<%- data.id %>"><?= /* @escapeNotVerified */ __('Remove') ?></label>
        </div>
    </div>

    <input type="hidden" name="js_uploaded_files[]" value="<%- data.temporary %>" />
</script>

<ul id="js-files-container" class="js-files-container ui-sortable" ></ul>

<script>
require([
    "jquery",
    "jquery/ui",
    "Magento_Theme/js/sortable",
    "Magento_Theme/js/custom-js-list"
], function(jQuery){

jQuery(function($) {
    $('.ui-sortable').sortable();
    $('.ui-sortable').disableSelection();

    $('#js-files-container').themeJsList({
        templateId : '#js-uploaded-file-template',
        refreshFileListEvent : 'refreshJsList',
        prefixItemId : 'js-file-'
    });
    $('body').trigger(
        'refreshJsList',
        {jsList: <?= /* @escapeNotVerified */ $this->helper('Magento\Framework\Json\Helper\Data')->jsonEncode($block->getJsFiles()) ?>}
    );
});

});
</script>