Retrieve response from a post using guzzle

I'm trying to get the response from a json porst with guzzle in a simple php.

This is the function in a laravel project that does the post for a url. (I'm using var_dump to show the result in the terminal).

public function getPhotos($properties)
{
    $codes = [];
    foreach($properties as $property)
    {
        $codes[$property['codigo']] = $property['cod_filial'];
    }
    $client = new Client();
    $response = $client->request('POST', 'http://local.app/file2.php', ['json' => \GuzzleHttp\json_encode($codes)]);
    var_dump($response); exit;
}

This is the php file mapped to http://local.app/file2.php

<?php
$input = file_get_contents('php://input');;
$input = json_decode($input);
echo $input;

The Guzzle me response empty. Can someone help me? Thanks