How to use CallbackInput channel?

Hi all i am beginner in rasa. Now i need to try callbackinput. In the rasa doc i saw this,

 # URL to which Core will send the bot responses
 url: "http://localhost:5034/bot"

My question is, in which file or where i can write controller function for the route http://localhost:5034/bot or http://myip:5005/mycustomcode

Thank you all.

You can write it anywhere you want. It is independent from the Rasa code. You just should implement the interface defined in Your Own Website. You need to start the controller next to Rasa. Otherwise Rasa will not be able to call the URL you defined in your credentials.yml.