1. Go to this page and download the library: Download mmeyer2k/secretbox library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
mmeyer2k / secretbox example snippets
use \Mmeyer2k\SecretBox\SecretBox;
$key = random_bytes(32); // 32 bytes SecretBox::decrypt($ciphertext, $key);