<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\Permission;
use Microsoft\Graph\Generated\Models\SharePointIdentitySet;
use Microsoft\Graph\Generated\Models\Identity;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new Permission();
$requestBody->setRoles(['reader', ]);
$grantedToV2 = new SharePointIdentitySet();
$grantedToV2User = new Identity();
$additionalData = [
'userPrincipalName' => 'jacob@fabrikam.com',
];
$grantedToV2User->setAdditionalData($additionalData);
$grantedToV2->setUser($grantedToV2User);
$requestBody->setGrantedToV2($grantedToV2);
$result = $graphServiceClient->storage()->fileStorage()->containers()->byFileStorageContainerId('fileStorageContainer-id')->permissions()->post($requestBody)->wait();