ENGCOM-5585: Resolve No asterisk symbol (required entry) when changing 'Encryption Key' (issue 24098) #24099

 - Merge Pull Request #24099 from edenduong/magento2:2.3-bugfix/asterisk_symbol_issue24098
 - Merged commits:
   1. fa78bfa

Author: magento-engcom-team

app/code/Magento/EncryptionKey/Block/Adminhtml/Crypt/Key/Form.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\EncryptionKey\Block\Adminhtml\Crypt\Key;
 
 /**
@@ -53,7 +55,14 @@ protected function _prepareForm()
         $fieldset->addField(
             'crypt_key',
             'text',
-            ['name' => 'crypt_key', 'label' => __('New Key'), 'style' => 'width:32em;', 'maxlength' => 32]
+            [
+                'name' => 'crypt_key',
+                'label' => __('New Key'),
+                'style' => 'width:32em;',
+                'maxlength' => 32,
+                'required' => true,
+                'class' => 'required-entry'
+            ]
         );
         $form->setUseContainer(true);
         if ($data = $this->getFormData()) {