By allowing the root in /etc/ssh/sshd_config/etc/ssh/sshd_config (Permit root login YesPermitRootLogin Yes).I, I was able to login.
according to man sshd_config
PermitRootLogin
Specifies whether root can log in using ssh(1). The argument must be “yes”, “prohibit-password”, “without-password”, “forced-commands-only”, or “no”. The default is “prohibit-password”. note that sshd must be restarted after a change in sshd_config.