Your VPS template includes VSFTPD as an FTP server. For convenience, root logins may be enabled, but this is insecure and should be turned off. Instead, use regular users and dedicated directories.
Disable root FTP access
Update the VSFTPD user list to remove root:
sudo nano /etc/vsftpd.userlist
Remove any root entry and save the file.
Then make sure root is listed in the FTP users deny file:
sudo nano /etc/ftpusers
Uncomment or add root if it is not already present, then save the file.
Adjust VSFTPD configuration
Open the main configuration file:
sudo nano /etc/vsftpd.conf
Find and remove the line:
allow_writeable_chroot=YES
Save the file, then restart the service so changes take effect:
sudo systemctl restart vsftpd
After this, configure non-root FTP users and shared folders according to your needs. For more examples and advanced settings, see the official VSFTPD documentation.