Create the events.xml file in your custom module and add the below code.
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
<event name="payment_method_is_active">
<observer name="cust_payment_disable" instance="VendorModuleObserverPaymentDisable" />
</event>
</config>
Create observer PaymentDisable.php file in your customer module and add below code.
<?php
namespace VendorModuleObserver;
use MagentoFrameworkEventObserver;
use MagentoFrameworkEventObserverInterface;
class PaymentDisable implements ObserverInterface {
protected $_customerSession;
public function __construct(
MagentoCustomerModelSession $customerSession,
MagentoCustomerModelGroupRegistry $groupRegistry
) {
$this->_customerSession = $customerSession;
$this->groupRegistry = $groupRegistry;
}
public function execute(Observer $observer) {
$payment_method_code = $observer->getEvent()->getMethodInstance()->getCode();
if ($payment_method_code == 'purchaseorder') {
$result = $observer->getEvent()->getResult();
if ($this->_customerSession->isLoggedIn()) {
$customer = $this->_customerSession->getCustomer();
$customerGroup = $customer->getGroupId();
if($customerGroup == 4){
$result->setData('is_available', false);
}
}
}
}
}
