There are other options for loading books onto the device via wifi. The package for rooting the device has a sshd daemon built into it. If you don't want to or can't root the device, you can get a separate sshd package in this thread:
https://www.mobileread.com/forums/sh...d.php?t=159636. If that doesn't work, there is a link to a thread where vsftpd is available towards the end of the sshd thread.