<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\TargetDeviceGroup;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new TargetDeviceGroup();
$requestBody->setOdataType('#microsoft.graph.targetDeviceGroup');
$requestBody->setId('b9e4eae4-b781-45a1-ce65-f2dd8ac3b696');
$requestBody->setDisplayName('Device Group A');
$result = $graphServiceClient->servicePrincipals()->byServicePrincipalId('servicePrincipal-id')->remoteDesktopSecurityConfiguration()->targetDeviceGroups()->post($requestBody)->wait();