use Stripe\Stripe;
$stripe = new Stripe("your_api_key");

use Stripe\Request\Cards\CreateCardRequest;

// create a customer
$request = $stripe->customers->createCustomerRequest();
$request->setEmail("[email protected]")->setDescription("A customer!");
$request->setCard(new CreateCardRequest("4242424242424242", 1, 2020));
$customer = $stripe->customers->createCustomer($request);
// get the newly-created customer's id
$customerId = $customer->getId();

// retrieve a customer
$customer = $stripe->customers()->getCustomer("customer_id");

// create a charge
$request = $stripe->charges->createChargeRequest(350, "usd")->setCustomer($customer->getId());
$stripe->charges->createCharge($request);

// retrieve a charge
$charge = $stripe->charges->getCharge("charge_id");