<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\Models\AuthenticationStrengthPolicy;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new AuthenticationStrengthPolicy();
$requestBody->setOdataType('#microsoft.graph.authenticationStrengthPolicy');
$requestBody->setDisplayName('FIDO2 only');
$requestBody->setDescription('An auth strength allowing only FIDO2 security keys.');
$result = $graphServiceClient->policies()->authenticationStrengthPolicies()->byAuthenticationStrengthPolicyId('authenticationStrengthPolicy-id')->patch($requestBody)->wait();