ACP2E-3233: Admin can still place order even without payment method

Author: Chhandak.Barua

app/code/Magento/Payment/Plugin/AdminSetPaymentMethod.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Payment\Plugin;
+
+use Magento\Framework\App\RequestInterface;
+use Magento\Sales\Model\AdminOrder\Create;
+
+/**
+ * Class PaymentConfigurationProcess
+ *
+ * Removes inactive payment methods and group from checkout configuration.
+ */
+class AdminSetPaymentMethod
+{
+    /**
+     * @param RequestInterface $request
+     */
+    public function __construct(
+        private readonly RequestInterface $request
+    ) {
+    }
+
+    /**
+     * Checkout LayoutProcessor before process plugin.
+     *
+     * @param Create $subject
+     * @param $data
+     * @return void
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function beforeImportPostData(Create $subject, $data)
+    {
+        if (!isset($data['payment_method']) && !isset($this->request->getParam('payment')['method'])) {
+            $subject->setPaymentMethod('');
+        }
+    }
+}

app/code/Magento/Payment/etc/adminhtml/di.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
+    <type name="Magento\Sales\Model\AdminOrder\Create">
+        <plugin name="AdminSetPaymentMethod" type="Magento\Payment\Plugin\AdminSetPaymentMethod"/>
+    </type>
+</config>

app/code/Magento/Sales/Model/AdminOrder/Create.php

@@ -1810,8 +1810,6 @@ public function importPostData($data)
 
         if (isset($data['payment_method'])) {
             $this->setPaymentMethod($data['payment_method']);
-       } else {
-            $this->setPaymentMethod('');
         }
 
         if (isset($data['coupon']['code'])) {