<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Sites\SitesRequestBuilderGetRequestConfiguration;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestConfiguration = new SitesRequestBuilderGetRequestConfiguration();
$queryParameters = SitesRequestBuilderGetRequestConfiguration::createQueryParameters();
$queryParameters->select = ["siteCollection","webUrl"];
$queryParameters->filter = "siteCollection/root ne null";
$requestConfiguration->queryParameters = $queryParameters;
$result = $graphServiceClient->sites()->get($requestConfiguration)->wait();