diff --git a/WebToPay.php b/WebToPay.php
index c654cf8..a32332e 100644
--- a/WebToPay.php
+++ b/WebToPay.php
@@ -1406,13 +1406,13 @@ class WebToPay_Factory
      */
     protected static array $defaultConfiguration = [
         'routes' => [
-            'production' => [
+            self::ENV_PRODUCTION => [
                 'publicKey' => 'https://www.paysera.com/download/public.key',
                 'payment' => 'https://bank.paysera.com/pay/',
                 'paymentMethodList' => 'https://www.paysera.com/new/api/paymentMethods/',
                 'smsAnswer' => 'https://bank.paysera.com/psms/respond/',
             ],
-            'sandbox' => [
+            self::ENV_SANDBOX => [
                 'publicKey' => 'https://sandbox.paysera.com/download/public.key',
                 'payment' => 'https://sandbox.paysera.com/pay/',
                 'paymentMethodList' => 'https://sandbox.paysera.com/new/api/paymentMethods/',
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..3901191
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,6 @@
+parameters:
+    level: 0
+    ignoreErrors:
+        - '#Fetching deprecated class constant .*#'
+    paths:
+        - src/
\ No newline at end of file