Class not found error

[hdr105]

I am getting this error

Fatal error: Uncaught Error: Class 'Craigslist\CraigslistRequest' not found in F:\xampp\htdocs\craigslist\index.php:11 Stack trace: #0 {main} thrown in F:\xampp\htdocs\craigslist\index.php on line 11

While running this code

use Craigslist\CraigslistRequest;
use Craigslist\CraigslistApi;

11: $request = new CraigslistRequest([
'city' => 'louisville',
'category' => 'pet',
'query' => 'pup'
]);
$api = new CraigslistApi();
$result = $api->get($request);

I am using php 7