CHUWI Mini PC Herobox and pfSense?

I got my new CHUWI Mini PC Herobox today and my thought was to use it as a router/firewall.
Using pfSense that is based on free/open-BSD. How do I force the unit to boot from USB?
I get into a Win10 install.

This cannot be changed, and it is not recommended that you change it. If you break the machine because of this, you may have to pay for maintenance.
Thank you for your letter

hold esc while booting (or F2) to get into the BIOS.
Here you can configure the boot device