Update app.py

app.py

@@ -3,12 +3,15 @@ import datetime
 import requests
 import pytz
 import yaml
+import os
 from tools.final_answer import FinalAnswerTool
 
 from Gradio_UI import GradioUI
 
 API_URL = "https://api-inference.huggingface.co/models/mistralai/Mistral-7B-Instruct-v0.2"
-headers = {"Authorization": "Bearer HF_TOKEN"}
+headers = {
+    "Authorization": f"Bearer {os.environ['HF_TOKEN']}",
+}
 
 @tool
 def extract_knowledge_graph(text: str) -> str: