Barry,
I tried that, the installer only seems to consider devices it detects as hard drives.
I have often installed Linux on USB memory "sticks". Boot the Live Linux
installer and check the status of the USB stick with "Disks". I have often
used Linux installs on USB sticks to rescue data from non-booting Windows
boxes, but now you can get external USB-C cases that hold NVME drives, and
cheap 128GB NVME left over after a larger drive was installed. These are much
faster than USB sticks.