1. Go to this page and download the library: Download pragmarx/yaml 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/ */
php
Yaml::parse($input, $flags) // Parses YAML into a PHP value.
Yaml::parseFile($filename, $flags) // Parses a YAML file into a PHP value.
Yaml::dump($input, $inline, $indent, $flags) // Dumps a PHP value to a YAML string.