To add a chrooted FTP user outside of Plesk properly, you need to:
- Create the user with the home directory as the root of what they can access
- Give the user a password
- Make their primary group psacln
- Add them to the psaserv group as well
# useradd username -d /var/www/html/website/slideshow/
# echo "password" | passwd username --stdin
Changing password for user username.
passwd: all authentication tokens updated successfully.
# usermod -g psacln username
# usermod -G psaserv username
# lftp username:password@localhost
lftp username@localhost:/> cd ..
lftp username@localhost:/>

Thank you ... this has me very helped.
Thank You very much!!!
Thank You for the post.
this helped me alot
There is an easier way to do this. Simply oper /etc/proftpd.conf and add this line:
after this one:
Substitute group with the user group to chroot in their home directories.
Don't forget you need to be logged in at the root baby
su -
right. ( i did so I am adding the comment for me when I come back in a year to add another user)