<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\EmailAuthenticationMethodConfiguration;
use Microsoft\Graph\Generated\Models\ExternalEmailOtpState;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new EmailAuthenticationMethodConfiguration();
$requestBody->setOdataType('#microsoft.graph.emailAuthenticationMethodConfiguration');
$requestBody->setAllowExternalIdToUseEmailOtp(new ExternalEmailOtpState('enabled'));
$result = $graphServiceClient->policies()->authenticationMethodsPolicy()->authenticationMethodConfigurations()->byAuthenticationMethodConfigurationId('authenticationMethodConfiguration-id')->patch($requestBody)->wait();