Undefined type 'Stripe\StripeClient' while integrating Stripe with my php project

Pardon me if this has been asked already. I am a beginner trying to integrate stripe payment gateway in my PHP sample project. I installed stripe API using composer from stripe github page. using composer require stripe/stripe-php in my project directory. require_once 'vendor/autoload.php'; is working just fine. but simple usage code is not working properly

 $stripe = new \Stripe\StripeClient('my secret key would be here');
    $customer = $stripe->customers->create([
        'description' => 'example customer',
        'email' => 'email@example.com',
        'payment_method' => 'pm_card_visa',
    ]);
    echo $customer;

1. cURL
2. JSON
3. mbstring
   are already installed and available in my system.

I tried solution described in this stack overflow post

but no positive results appeared. Thanks in advance.

>Solution :

try like this:

require_once('/stripe-php-master/init.php');

\Stripe\Stripe::setApiKey('stripe_sectet_key');


$customer = \Stripe\Customer::create([
    'description' => 'example customer',
    'email' => 'email@example.com',
    'payment_method' => 'pm_card_visa',
]);

echo $customer;