PR4100(frimware ver5): how to boot from USB?

So, I have bootable USB (checked on my laptop), but I can’t boot it in my PR4100.
How to do it?

PR4100 boots only self OS everytime…

Hi @Vantela,

Please refer to the article Problems booting a PC with an external USB drive connected:

For more information, please contact the WD Technical Support team for best assistance and troubleshooting:

So, I can concrete my question. How to create bootable USB for PR4100?
I can burn(to USB) images was created by other people.
But my images (ubuntu server, truenas, freenas, OMV) can’t be booted…