1. Enable Password Authentication
1.1. Update “PasswordAuthentication:yes” in sshd_config
sudo vi /etc/ssh/sshd_config
1.2. Assign password to main user
sudo passwd [USERNAME] # for ec2 its ubuntu
1.3. Restart sshd service
sudo service sshd restart
2. Configure vsftpd to allow access
2.1. sudo vi /etc/vsftpd.conf
and adds following
listen=YES
listen_ipv6=NO
write_enable=YES
allow_writeable_chroot=YES
2.2. Restart vsftpd service
sudo service vsftpd restart
Now you should be able to login from main user by using host, username and password.
3. Add new FTP User and Setup Access
adduser [NEW_USERNAME]
# set user home directory - if needed
sudo usermod -d [LOCATION][NEW_USERNAME]
# give group permissions - if needed
usermod -a -G [GROUP_NAME] [NEW_USERNAME]
# restart service
sudo systemctl restart vsftpd
Now you should also be able to login with this new FTP user.