How do I install Kali Linux (Not Live) onto a USB?

The last few days I’ve been trying to install Kali onto an empty flash drive. I flash a second drive and run the graphical installer, choose the empty flash drive as the disk to install onto as well as the device to install grub onto. After the installation process I try to boot from the drive through Windows boot manager. However, after selecting the correct boot device I get a black screen with a blinking “_” in the corner. I’ve searched the internet extensively and tried some potential solutions but with no success. Most solutions suggest editing the grub settings, but I never get to the grub menu. Does anyone know of a solution to this? Thanks in advance!