changed double to single quotes

Author: jamesbramich

Helper/Data.php

@@ -76,7 +76,7 @@ public function createPaymentRequest(Order $order): array
         $amount = $order->getTotalDue();
         $customerEmail = $order->getCustomerEmail();
         $currency = $order->getOrderCurrencyCode();
-        $paymentMethodTypes = array("card", "pisp");
+        $paymentMethodTypes = array('card', 'pisp');
         $originUrl = $this->url->getBaseUrl(['_store' => $storeId]);
         $nofrixionOrderId = $this->encodeOrderId($order);
         $callbackUrl = $this->url->getUrl('nofrixion/redirect/returnAfterPayment', ['_secure' => true, 'nofrixion_order_id' => $nofrixionOrderId]);