<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\FederatedIdentityCredential;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new FederatedIdentityCredential();
$requestBody->setName('testing02');
$requestBody->setIssuer('https://login.microsoftonline.com/3d1e2be9-a10a-4a0c-8380-7ce190f98ed9/v2.0');
$requestBody->setSubject('a7d388c3-5e3f-4959-ac7d-786b3383006a');
$requestBody->setDescription('Updated description');
$requestBody->setAudiences(['api://AzureADTokenExchange', ]);
$result = $graphServiceClient->applications()->byApplicationId('application-id')->federatedIdentityCredentials()->byFederatedIdentityCredentialId('federatedIdentityCredential-id')->patch($requestBody)->wait();