JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://dev.sencha.com/deploy/ext-3.4.0/resources/css/ext-all.css">

JavaScript

Ext.onReady(function() {

    var store = new Ext.data.ArrayStore({
        id: 0,
        fields: [
            'myId',
            'displayText'
        ],
        data: [
            [1, '1'],
            [2, '2'],
            [3, '3'],
        ]
    });

           var scriptField = {
                xtype: 'fieldset',
                columnWidth: '0.5',
                title: 'Script Details',
                items: [{
                    xtype: 'textfield',
                    fieldLabel: 'Script Name',
                    hiddenName: 'scriptName'
                }]            
    };
            
    var container = new Ext.Panel({
        layout: 'hbox',
        height: '700px',
        items: [{
            xtype: 'panel',
            id: 'parentContainer',
            height: '700px',
            layout: 'form',
            items: [{
                xtype: 'combo',
                editable: false,
                triggerAction: 'all',
                mode: 'local',
                store: store,
                valueField: 'myId',
                displayField: 'displayText',
                fieldLabel: 'Show Number of Items',
                listeners: {
                    select: function(combo, value) {
                        var dynamicPanel = Ext.getCmp("dynamicPanel");
                        dynamicPanel.removeAll(true);
                        dynamicPanel.doLayout();
                        dynamicPanel.ownerCt.doLayout();
                        dynamicPanel.ownerCt.ownerCt.doLayout();
                        for (var i = 0; i < combo.getValue(); i++) {
                            dynamicPanel.add(scriptField);
                            dynamicPanel.doLayout();
                            dynamicPanel.ownerCt.doLayout();
                            dynamicPanel.ownerCt.ownerCt.doLayout();
                        }
                    }
                }
            }, {
            xtype: 'panel',
            id:'dynamicPanel',
           ...