diff --git a/app/Http/Controllers/Manager/OrdersController.php b/app/Http/Controllers/Manager/OrdersController.php
index 261359d..b6912de 100644
--- a/app/Http/Controllers/Manager/OrdersController.php
+++ b/app/Http/Controllers/Manager/OrdersController.php
@@ -836,7 +836,7 @@ class OrdersController extends CommonController
         }
         return response()->json([
             "errorcode" => 30000,
-            "errormsg" => $to_generate_days
+            "errormsg" => "{$to_generate_days}"
         ]);
         $to_generate_days = max(0, $to_generate_days);
         $prepay_total = $unpaid_order_items->sum("total") + $to_generate_days * $order->price;