$stripe = new \Stripe\StripeClient('sk_test_51KX5RA...CV00KMzNeBbs sk_test_51KX5RAHpz0yDkAJjgP65eUwiAJMY1mHeA4LoeX6162wxO6RDyGFZaQR6mOY1X9e7PpVAXkC1AT1HWNfE7ri3HRCV00KMzNeBbs '); $stripe->customers->update( 'cus_NffrFeUfNV2Hib', ['metadata' => ['order_id' => '6735']] );