Solution
We need a username, host key, password GUID, and URL of the FTP server to create a connection with Netsuite and FTP.
Generate host key and Password GUID using this Suitelet below
See an example below
var userName = 'brenna.mitchell@oxtools.com'; // username of FTP server that used for logging in to FTP
var URL = 'in1.hostedftp.com'; // URL of FTP server
var hostKey = 'AAAAB3NzaC1yc2EAAAADAQABAAABAQC4ZIMHa5GWDaRmXAxhG8rAU6VrSNSanEDVk2O+h22dJIPZsaNl9jc0kll4WeB4hbsjISiyjAKRpK6oHiGF8I2ImRFFjGS7/fUnoLMPEWF2asJ6YnsTZvOX+wR1aCJNAg9nwhJVH6uznVmQ/M2ZrkY64G7C2UHY+hQYHouLRRdY6KiQuM4R/Z5SdN5BKjJhKLYHU5p/GaU7n/JwzkUHrVazdvNEZaQhiQpIK+YmnHZZAbyzY9WHn/lsQ4KskFkkadhUUKws2J8D0uIlLJZW0XwG2mpjXt+sTUfQdL94jWo+/sdvGdjdL0cHXVxOUpO7K07moIxsPqNvCNzZYBugm/0v'
var passGUID = '1a3e355f43564c2c95c4d4d0d0f2e3f5';
var connection = sftp.createConnection({
username: userName,
passwordGuid: passGUID,
url: URL,
directory: '/',
hostKey: hostKey
});
log.debug("connection", connection);