How to boot FreeBSD installed on the sd card on the Khadas Edge-V instead of Android

Hello.

I’ve got the board Khadas Edge-V to my home. I’ve installed FreeBSD on the
sd card and I would like to boot from it. But everytime that I turn on the
board,Android boots instead of FreeBSD. How can I boot the board from the
sd card ?

From here :

https://forum.khadas.com/t/how-to-boot-an-os-from-the-sd-card-instead-of-android/25074

I read that :

Disconnect the power supply, insert the SD card, access the power supply,
and press the Function Button three times within five seconds.Will boot
from SD card

I tried,but it did not work. On my keyboard I don’t have a Function
Button,but the F (1-12) keys. Which one is the right one ?

Thanks for your help.

-- 
Mario.