diff --git a/litellm/proxy/_types.py b/litellm/proxy/_types.py
index 39f65ac2dfa..e4407f7206b 100644
--- a/litellm/proxy/_types.py
+++ b/litellm/proxy/_types.py
@@ -1638,6 +1638,7 @@ class AllCallbacks(LiteLLMBase):
             "LAGO_API_BASE",
             "LAGO_API_KEY",
             "LAGO_API_EVENT_CODE",
+            "LAGO_API_CHARGE_BY",
         ],
         ui_callback_name="Lago Billing",
     )