$stripe = new \Stripe\StripeClient(
  'sk_test_51Ii3pgL2sxxCMmgwSpETIPllrbwqqHE6aI86Gg5Fm9FKvDDrjypwMsgPNGtKKv7PeJb9gsFpfcbhRc091tdQZb3100snPwkSPH'
);
$stripe->charges->create([
  'amount' => 2000,
  'currency' => 'usd',
  'source' => 'tok_mastercard',
  'description' => 'My First Test Charge (created for API docs)',
]);