I can not install set up Qubes OS

Hello all !!
I created Qubes OS boot USB. This is OK. But, It did not show option USB of installation in Qubes OS install page. It show only PC memory(almost 400gb free). I use USB(64gb) device. But it don`t show.
What should I do? I just want to install Qubes OS to USB device not PC.
Advice please. And sorry my English.

You can switch to TTY with Ctrl+Alt+F2 and check the logs in terminal to see what’s the problem with your USB drive.

sorry late reply. And thank you advice. I think USB is no problem. Because it is new. Also , I try it. thank you.