fix:key

@@ -16,10 +16,13 @@ class MinPayment
      */
     protected $client;
 
+    private $config = [];
+
 
     public function __construct(array $config = [])
     {
-        $this->client = new Client($config + (array)\config('min-payment'));
+        $this->config = $config + (array)\config('min-payment');
+        $this->client = new Client($this->config);
     }
 
     /**
@@ -85,7 +88,8 @@ class MinPayment
     {
         $sign = \Arr::get($input, $signName);
         unset($input[$signName]);
+        $secret = \Arr::get($this->config, 'secret');
 
-        return Signature::make($input) === $sign;
+        return Signature::make($input, $secret) === $sign;
     }
 }