<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\Models\AccessPackageAssignmentRequest;
use Microsoft\Graph\Beta\Generated\Models\AccessPackageAssignment;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new AccessPackageAssignmentRequest();
$requestBody->setRequestType('UserAdd');
$accessPackageAssignment = new AccessPackageAssignment();
$accessPackageAssignment->setAccessPackageId('a914b616-e04e-476b-aa37-91038f0b165b');
$requestBody->setAccessPackageAssignment($accessPackageAssignment);
$requestBody->setJustification('Need access to New Hire access package');
$result = $graphServiceClient->identityGovernance()->entitlementManagement()->assignmentRequests()->post($requestBody)->wait();