In the Linux terminal of WSL2, sometimes a fixed hard drive is visible, but a USB drive is not visible (which may be the case in most cases).
Even though it appears to be properly attached to the host Windows, if it does not appear in the WSL2 Linux terminal, do the following:
Assuming that the USB drive is recognized as drive F in Windows.
sudo mkdir /mnt/f
sudo mount -t drvfs f: /mnt/f