Composer

Add PDFParser to your composer.json file :

{
    "require": {
        "smalot/pdfparser": "*"
    }
}

Now ask for composer to download the bundle by running the command:

$ composer update smalot/pdfparser

Without Composer

In case you can't use Composer, you can include alt_autoload.php-dist into your project. It will load all required files at once. Afterwards you can use PDFParser class and others.

<?php
 
require __DIR__.'/../alt_autoload.php-dist';
 
// Your code
// ...
 
?>