504 error?

app.py

@@ -2,7 +2,8 @@ import gradio as gr
 from uuid import uuid4 as uuid
 from huggingface_hub import HfApi
 from typing import Any
-from griptape.structures import Agent
+from griptape.structures import Agent, Workflow
+from griptape.tasks import PromptTask
 from griptape.drivers import LocalConversationMemoryDriver
 from griptape.memory.structure import ConversationMemory
 from griptape.tools import Calculator
@@ -41,7 +42,17 @@ agent = Agent(
             ) ]
 )
 
-gr.State()
+workflow = Workflow()
+start_task = PromptTask("I will provide you two dog breeds to compare", id="START")
+end_task = PromptTask("How are the dog breeds different", id="END")
+workflow.add_task(start_task)
+workflow.add_task(end_task)
+dog_task = PromptTask("Poodle and a Labrador", id="DOG")
+workflow.insert_tasks(start_task,[dog_task],end_task)
+
+def use_workflow(message:str, history) -> Any:
+    response = workflow.run()
+    return response.output.value
 
 def send_message(message:str, history,) -> Any:
     response = agent.run(message)