<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\Channel;
use Microsoft\Graph\Generated\Models\ChannelMembershipType;
use Microsoft\Graph\Generated\Models\ConversationMember;
use Microsoft\Graph\Generated\Models\AadUserConversationMember;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new Channel();
$requestBody->setOdataType('#Microsoft.Graph.channel');
$requestBody->setMembershipType(new ChannelMembershipType('private'));
$requestBody->setDisplayName('My First Private Channel');
$requestBody->setDescription('This is my first private channels');
$membersConversationMember1 = new AadUserConversationMember();
$membersConversationMember1->setOdataType('#microsoft.graph.aadUserConversationMember');
$membersConversationMember1->setRoles(['owner', ]);
$additionalData = [
'user@odata.bind' => 'https://graph.microsoft.com/v1.0/users(\'jacob@contoso.com\')',
];
$membersConversationMember1->setAdditionalData($additionalData);
$membersArray []= $membersConversationMember1;
$requestBody->setMembers($membersArray);
$result = $graphServiceClient->teams()->byTeamId('team-id')->channels()->post($requestBody)->wait();