Asus Prime x570-Pro how to enter boot options?

[Operations]

I know it is a silly question but i cannot find the answer

Of course i know how to change the boot order in the BIOS or how to select a different device for the next boot from the BIOS.

But which F key is the one to quickly open the boot options during booting? I have tried F7, F8, F9, F10, F11 and F12.
Sometimes i need to boot from a different device and i would like to do this without having to enter the BIOS.

 

[ashmelev75]

F8, only works from cold boot.

 

[Dreamerbydesign]

Usually F1