<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\Call;
use Microsoft\Graph\Generated\Models\ParticipantInfo;
use Microsoft\Graph\Generated\Models\IdentitySet;
use Microsoft\Graph\Generated\Models\Identity;
use Microsoft\Graph\Generated\Models\InvitationParticipantInfo;
use Microsoft\Graph\Generated\Models\Modality;
use Microsoft\Graph\Generated\Models\AppHostedMediaConfig;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new Call();
$requestBody->setOdataType('#microsoft.graph.call');
$requestBody->setCallbackUri('https://bot.contoso.com/callback');
$source = new ParticipantInfo();
$source->setOdataType('#microsoft.graph.participantInfo');
$sourceIdentity = new IdentitySet();
$sourceIdentity->setOdataType('#microsoft.graph.identitySet');
$sourceIdentityApplication = new Identity();
$sourceIdentityApplication->setOdataType('#microsoft.graph.identity');
$sourceIdentityApplication->setDisplayName('Calling Bot');
$sourceIdentityApplication->setId('2891555a-92ff-42e6-80fa-6e1300c6b5c6');
$sourceIdentity->setApplication($sourceIdentityApplication);
$source->setIdentity($sourceIdentity);
$source->setRegion(null);
$source->setLanguageId(null);
$requestBody->setSource($source);
$targetsInvitationParticipantInfo1 = new InvitationParticipantInfo();
$targetsInvitationParticipantInfo1->setOdataType('#microsoft.graph.invitationParticipantInfo');
$targetsInvitationParticipantInfo1Identity = new IdentitySet();
$targetsInvitationParticipantInfo1Identity->setOdataType('#microsoft.graph.identitySet');
$targetsInvitationParticipantInfo1IdentityUser = new Identity();
$targetsInvitationParticipantInfo1IdentityUser->setOdataType('#microsoft.graph.identity');
$targetsInvitationParticipantInfo1IdentityUser->setDisplayName('John');
$targetsInvitationParticipantInfo1IdentityUser->setId('112f7296-5fa4-42ca-bae8-6a692b15d4b8');
$targetsInvitationParticipantInfo1Identity->setUser($targetsInvitationParticipantInfo1IdentityUser);
$targetsInvitationParticipantInfo1->setIdentity($targetsInvitationParticipantInfo1Identity);
$targetsArray []= $targetsInvitationParticipantInfo1;
$requestBody->setTargets($targetsArray);
$requestBody->setRequestedModalities([new Modality('audio'),]);
$mediaConfig = new AppHostedMediaConfig();
$mediaConfig->setOdataType('#microsoft.graph.appHostedMediaConfig');
$mediaConfig->setBlob('<Media Session Configuration>');
$requestBody->setMediaConfig($mediaConfig);
$result = $graphServiceClient->communications()->calls()->post($requestBody)->wait();