systemctl start sshd.service
scp /home/user/asdf.log user@127.0.0.1:/home/user/test/asdf.log
...
zsh:1: command not found: scp

ssh user@127.0.0.1 ls
...
zsh:1: command not found: ls

ssh root@127.0.0.1 ls
...
Desktop
Documents
Music
...

#/etc/ssh/sshd_config
PermitRootLogin yes # this is bad; for testing only
AuthorizedKeysFile  .ssh/authorized_keys
ChallengeResponseAuthentication no
UsePAM yes
PrintMotd no #pam does that
Subsystem sftp /usr/lib/ssh/sftp-server