CallBack URL returns 404 error

I have deployed Istio BookInfo App on Azure Kubernetes Cluster as per this blog post on securing K8 with Istio and Auth0.

Everything seems to be working OK till I reach the stage when after successfully signing into Auth0, When i get redirected to the CallBack URL, i get

No webpage was found for the web address: http://40.121.3.206/callback?code=zMzVLGnii8l-3gy7&state=LXVdAHQRuCX6lrgCD3DSZBduf5pY89

I need to finish my POC soon so any help is much appreciated.

For some reason, when redirecting the callback code in the python app is not triggered.

@app.route(’/callback’)
def callback():
response = auth0.authorize_access_token() # 1
session[‘access_token’] = response[‘access_token’] # 2
userinfoResponse = auth0.get(‘userinfo’) # 3
userinfo = userinfoResponse.json()
session[‘user’] = userinfo[‘nickname’] # 4
return redirect(’/productpage’)