You can create and Custom Module or can use your custom theme to implement your requirement.
I assume your using a custom module and I also assume your Custom Module Name is Company_CheckoutCustomtext
You can follow the steps as described below.
step 1)
Create checkout_index_index.xml under YOUR-MAGENTO-ROOT/app/code/Company/CheckoutCustomtext/view/frontend/layout
File : *app/code/Company/CheckoutCustomtext/view/frontend/layout/checkout_index_index.xml*
<?xml version="1.0"?>
<!--
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
-->
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="checkout.root">
<arguments>
<argument name="jsLayout" xsi:type="array">
<item name="components" xsi:type="array">
<item name="checkout" xsi:type="array">
<item name="children" xsi:type="array">
<item name="sidebar" xsi:type="array">
<item name="children" xsi:type="array">
<item name="summary" xsi:type="array">
<item name="component" xsi:type="string">Magento_Checkout/js/view/summary</item>
<item name="displayArea" xsi:type="string">summary</item>
<item name="config" xsi:type="array">
<item name="template" xsi:type="string">Magento_Checkout/summary</item>
</item>
<item name="children" xsi:type="array">
<item name="itemsBefore" xsi:type="array">
<item name="component" xsi:type="string">uiComponent</item>
<item name="children" xsi:type="array">
<!-- merge your components here -->
<item name="checkout-mycustomtext" xsi:type="array">
<item name="component" xsi:type="string">Company_CheckoutCustomtext/js/view/checkout-mycustomtext</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</argument>
</arguments>
</referenceBlock>
</body>
</page>
Step 2)
Create the js Component file checkout-mycustomtext.js under YOUR-MAGENTO-ROOT/app/code/Company/CheckoutCustomtext/view/frontend/web/js/view/
File : /app/code/Company/CheckoutCustomtext/view/frontend/web/js/view/checkout-mycustomtext.js
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
define([
'jquery',
'ko',
'uiComponent',
'Magento_Checkout/js/model/quote',
'Magento_Checkout/js/checkout-data',
'Magento_Customer/js/customer-data',
'mage/translate'],
function($, ko, Component, quote, checkoutData, customerData, $t){
return Component.extend({
defaults: {
template: 'Company_CheckoutCustomtext/sales/checkout/mycustomtext'
},
getCustomText: function (){
var customText = $t('Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged');
return customText;
}
});
});
Step 3)
Now create your custom js component's template file mycustomtext.html under YOUR-MAGENTO-ROOT/app/code/Company/CheckoutCustomtext/view/frontend/web/template/sales/checkout/
File : /app/code/Company/CheckoutCustomtext/view/frontend/web/template/sales/checkout/mycustomtext.html
<p data-bind="text: getCustomText()" style="font-weight:bold;"></p>
step 4)
Now run the command below
sudo php bin/magento setup:upgrade
sudo php bin/magento setup:di:compile
sudo php bin/magento setup:static-content:deploy
Demo :
