Your chatbot account is permanently tied to a Xenioo server node.
Any call you make to the custom channel must be directed to your chatbot node or it will fail.
Your server node is the same you see on the address bar when you're logged in Xenioo (e.g. app, app02 etc).
If your server address is, for example, app03.xenioo.com, then you must use the same address.