Webhook in lambda api gateway for sns

sns_webhook.php

<?php

require 'path/to/vendor/autoload.php';

use AwsSnsMessageValidatorMessage;
use AwsSnsMessageValidatorMessageValidator;
use GuzzleHttpClient;

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    die;
}

try {
   
    $message = Message::fromRawPostData();
    $validator = new MessageValidator();
    $validator->validate($message);
} catch (Exception $e) {
   
    http_response_code(404);
    die;
}

if ($message->get('Type') === 'SubscriptionConfirmation') {
  
    (new Client)->get($message->get('SubscribeURL'))->send();
} elseif ($message->get('Type') === 'Notification') {
  //Save this to your DB if you want too
    save_message_to_database($message);
}