This change stopped the Runtime error for me, although getting a 504 when calling the Llama model.

run.py

@@ -1,12 +1,16 @@
 import gradio as gr
 from gradio import ChatMessage
-from transformers import load_tool, ReactCodeAgent, HfEngine  # type: ignore
+from transformers import load_tool, ReactCodeAgent, HfApiEngine  # type: ignore
 from utils import stream_from_transformers_agent
+import os 
+
+HF_TOKEN = os.environ.get("HF_TOKEN")
 
 # Import tool from Hub
 image_generation_tool = load_tool("m-ric/text-to-image")
 
-llm_engine = HfEngine("meta-llama/Meta-Llama-3-70B-Instruct")
+llm_engine = HfApiEngine(model="meta-llama/Meta-Llama-3-70B-Instruct", token=HF_TOKEN)
+
 # Initialize the agent with both tools
 agent = ReactCodeAgent(tools=[image_generation_tool], llm_engine=llm_engine)