In order to integrate with Twitter, your Kegbot Server needs to be accessible on the public internet.
If you have a standard home network configuration where your ISP provides a single dynamic IP address, you will need to configure your Wifi/Wired router to forward incoming request to your public IP address on port 80 to the IP address of your Kegbot Server.
Once you’ve configured port-forwarding correctly, you should be able to connect to your Kegbot Server from anywhere by opening a web browser and navigating to the public IP Address assigned to you by your ISP. You can easily find this by visiting https://www.whatismyip.com/.
Once you’ve confirmed that is working, you can then use a service like NOIP.com to create a free hostname that maps to your IP address, rather than having to remember the IP address yourself.
If you run into issues, just google how to setup port forwarding to a server inside your network.
After all that is completed and you can access kegbot from the web, the twitter callback URL will be http://[PUBLIC URL]/kegadmin/plugin/twitter/. Where the PUBLIC URL is your public IP address or the name you setup with NOIP.