How to use api rest with php

I am new to the issue of using api rest of redmine and I need to give a project that shows the services that are in that project, to be able to later operate on said services, the case is that for more than I try to extract info I always it comes out or Syntax error, or I do not get anything in my browser, and I think I'm not using it correctly or correctly, here's my sample code:

require_once 'php-redmine-api-master/lib/autoload.php';

// Instantiate a redmine client
// --> with ApiKey
$client = new Redmine\Client('http://url.es', 'api_key'); 

print_r($client);


// Trackers
$trackers = $client->tracker->all();
//var_dump($trackers);


$project_id = 119;
$issues = $project_id->issue->all(['project_id' => $project_id]);



print_r($issues);

Can you tell me how to list even the list of projects when I access from my localhost to the web that I need to access? I'm pretty fish, thank you.

PS: the client print r if you take out information and I understand it goes well.