Update app.py

app.py

@@ -63,7 +63,8 @@ def send_request(agent_url, request_type, message_text="Hello, this is a test me
             envelope = build_utterance_envelope(agent_url, message_text)
         
         # Convert to JSON using the library's method
-        envelope_dict = envelope.to_dict()
+        json_str = envelope.to_json()
+        envelope_dict = json.loads(json_str)
         json_payload_pretty = json.dumps({"openFloor": envelope_dict}, indent=2)
         
         # Send request