diff --git a/UI_V2/flask_server.py b/UI_V2/flask_server.py
index c51604d..5bef28f 100644
--- a/UI_V2/flask_server.py
+++ b/UI_V2/flask_server.py
@@ -5,6 +5,7 @@ import logging
 from logging.handlers import RotatingFileHandler
 from flask import Flask, request, jsonify
 from flask_cors import CORS
+from flask import Response
 
 try:
     from dotenv import load_dotenv
@@ -31,16 +32,28 @@ app.logger.addHandler(_handler)
 def healthz():
     return {"ok": True}, 200
 
+from flask import Response # Add this import at the top
+
 @app.post("/api/payments/ipn")
 def ipn():
     try:
-        # Pass the whole request object, not just request.data
+        # 1. Verify the request with the SDK
         data = verify_ipn(request) 
         app.logger.info("IPN OK: %s", data)
-        return jsonify({"ok": True, "data": data}), 200
+        
+        # 2. Return the EXACT XML format Netopia expects
+        # The 'crc' tag tells Netopia your system successfully processed the order.
+        xml_response = '<?xml version="1.0" encoding="utf-8" ?><crc>ok</crc>'
+        
+        return Response(xml_response, mimetype='application/xml'), 200
+
     except Exception as e:
         app.logger.exception("IPN verification failed: %s", e)
-        return jsonify({"ok": False, "error": str(e)}), 400
+        
+        # If there's an error on your side, you can signal a temporary failure
+        # error_type="1" means "Temporary Error, please retry later"
+        error_xml = '<?xml version="1.0" encoding="utf-8" ?><crc error_type="1">Internal Error</crc>'
+        return Response(error_xml, mimetype='application/xml'), 400
 
 
 @app.get("/api/payments/status")
diff --git a/UI_V2/requirements.txt b/UI_V2/requirements.txt
index c32016c..77c48f0 100644
--- a/UI_V2/requirements.txt
+++ b/UI_V2/requirements.txt
@@ -2,4 +2,5 @@ flet==0.28.3
 netopia-sdk==2.1.1
 python-dotenv==1.2.0
 Flask==3.1.2
-flask-cors==6.0.1
\ No newline at end of file
+flask-cors==6.0.1
+flet-audio-0.1.0
\ No newline at end of file