I guess it is not possible.. Found this article on vendor site
"- Can the JetFlash be used as a bootable flash drive?"
"JetFlash series aims at being a portable storage device and not as a
bootable drive. No exclusive software tool is provided either."
From: Аладышев Константин [mailto:firstname.lastname@example.org]
Sent: Thursday, May 17, 2018 2:50 PM
I'm having problems with USB boot from Transcend JetFlash 620 drive 32GB.
SeaBIOS doesn't see it as boot device. I suppose the problem is in
SecureDrive technology that is used on this device. I tried to remove it
with "CD-ROM Remover_v220.127.116.11" tool that I've found. It removed CD
from OS, but SeaBIOS still can't see flash drive as boot device.
Does someone know how to solve this issue?