hi I'm using php code and downloaded the Unirest from github and i followed the instruction and still don't know how to use this api

<?php

require_once ('unirest-php\src\Unirest.php');

$response = Unirest\Request::get("https://andruxnet-random-famous-quotes.p.mashape.com/?cat=famous",
array(
"X-RapidAPI-Key" => "b6tCZGODOTmshRX3SGwKX39eANfup1NqESSjsnPp9aB0mxbvHF"
)
);

echo $response

?>
can you help me