Ubuntu live sessions do not retain data or any applications installed on it after shutdown You do know this, do you not? You would have to install Ubuntu on to the USB memory stick.
I would like to quote from the Openclaw web site
Clears your inbox, sends emails, manages your calendar, checks you in for flights.
All from WhatsApp, Telegram, or any chat app you already use.
Sounds useful does it not? Giving that power to a program that is unavailable in the Ubuntu Software Center frightens me.
Do you have any detail about how you add the persistence? I hope some day the USB Creator tool will have an option to enable persistence natively instead of doing hacks and workarounds.