How to boot from USB? No such option in BIOS

Hi,
a few days ago i´ve bought the Chuwi Corebook Pro. The Notebook is nice, I like it but there´s one big problem. I cannot boot from USB to install another OS. There´s no option in BIOS/UEFI to choose USB as boot option. How can I do it? Can somebody help?
If I can´t replace the preinstalled Win 10 with an reasonable OS, I´m forced to sell it again.

Hello, is the usb usable normally, have you tried to replace it with another usb? thanks