In order to setup smart autoresponder please visit https://script.google.com/, create "New script" and copy "src/responder.js" code into editor, name your project and save changes.
Save changes and run your code, google scripts will show you authorization dialog.
Smart Autoresponder needs your permission to access your data on Google.
Now you need to setup project triggers for function "main" (small clock icon in editor).
| main | Time-driven | Minutes timer | Every 5 minutes |
This configuration will run autoresponder script every 5 minutes.
By default autoresponder will be active from Mon-Fri between 8am - 8pm.