To install Pure-FTPd in Ubuntu, run

apt-get install pure-ftpd

To enable system users login to FTP, run

echo "yes" > /etc/pure-ftpd/conf/UnixAuthentication
echo "yes" > /etc/pure-ftpd/conf/NoAnonymous
echo "yes" > /etc/pure-ftpd/conf/ChrootEveryone
echo "yes" > /etc/pure-ftpd/conf/IPV4Only

Now restart pure-ftpd

service pure-ftpd stop
service pure-ftpd start

To create a user, run

useradd --home /path/to/home/dir/ --shell /bin/bash USER_NAME_HERE

For Example

root@server2:~# useradd --home /home/urltv.tv/ urltv
root@server2:~# passwd urltv
Enter new UNIX password: 
Retype new UNIX password: 
passwd: password updated successfully
root@server2:~# 

Once user is created, you need to set password with command passwd.