Follow these steps to set your playbook as the default playbook:
Navigate to AI-Builder from left menu with icon
You will see list of playbooks. Scroll down till you see the playbook named "Default". In front of this playbook, you will see an event named "default" as shown below.
Remove this default event.
Now scroll down to the playbook you created. Add the default event to your travel playbook.
And you are done. The new playbook you created will become the default playbook for your website.