Open the floating bubble at bottom-right. Try sending a message.
Paste this snippet somewhere before </body> on the target site (replace https://YOUR-BACKEND-HOST):
<script src="https://YOUR-BACKEND-HOST/widget/chatbot.js" data-backend-url="https://YOUR-BACKEND-HOST"></script>
The widget JS is served at /widget/chatbot.js and the demo sets the backend to this origin.