updated name of api token

app.py

@@ -15,7 +15,7 @@ LEPTON_API_TOKEN = os.environ.get("LEPTON_API_TOKEN", None)
 # Set up client to call inference
 client=openai.OpenAI(
     base_url="https://yb15a7dy-lynx-70b.tin.lepton.run/api/v1/",
-    api_key=api_token
+    api_key=LEPTON_API_TOKEN
 )
 
 # Create own model