1. Go to this page and download the library: Download duosecurity/duo_php 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/ */
duosecurity / duo_php example snippets
$ git clone https://github.com/duosecurity/duo_php.git
$ cd duo_php
$ composer install