diff --git a/commands/product.py b/commands/product.py
index abb76e1..9b7a239 100755
--- a/commands/product.py
+++ b/commands/product.py
@@ -12,7 +12,7 @@ def product():
 
 @product.command("list")
 def list():
-    r = requests.get(f"{config('UCLOUD_PAY_SERVER')}/product/list")
+    r = requests.get("{}/product/list".format(config('UCLOUD_PAY_SERVER')))
     print(load_dump_pretty(r.content))
 
 
@@ -44,5 +44,6 @@ def add(name, realm, seed, product_name, product_description, product_type,
         "product_recurring_duration": product_recurring_duration,
         "product_recurring_duration_units": product_recurring_duration_units
     }
-    r = requests.post(f"{config('UCLOUD_API_SERVER')}/product/add", json=data)
+    r = requests.post("{}/product/add".format(config('UCLOUD_API_SERVER')),
+                      json=data)
     print(load_dump_pretty(r.content))