This file has a line: AllowUsers admin and it is that line which limits SSH logins to the user admin. SSH configuration is controlled by the file /etc/ssh/sshd_config. By default, the QNAP device refuses ssh connections from any other user ID.
You can open the ssh link on the command line by using ssh (I think you know this already) if you want to access it via nautilus in gnome then you can minimise all windows and do +L which will open a dialog.To have the new user's public key added to the list of keys that are authorized to use his account, check the *Copy new identify.pub to authorized_keys* box. Check the Setup SSH key for new Unix users checkbox, so that ssh-keygen will be run for new accounts. On the module's main page, click on the User SSH Key Setup icon.
You can try one of these free shell providers (update, this site is no longer available) from this list.
USER MANAGEMENT Graphical user management system-config-users Create user account useradd Delete user account userdel Change user account details usermod View user account details usermod /etc/passwd Create user group groupadd Delete user group groupdel Change group details groupmod Change user password passwd username Change user permissions.Under Advanced Options on the Create Server page, click Manage SSH Keys. If your key is not already in the list, you may add it, and then assign it. When you create a cloud server, you can assign a public key from the list of keys. Specify your SSH key when creating a new cloud server.Users can select SSH settings from the Credentials menu and enter credentials for scanning Linux systems. Nessus supports five types of authentication methods for use with SSH: username and password, public/private keys, digital certificates, and Kerberos.The user name to use when connecting to the host. The connection port number, if not the default (22 for ssh) ansible_user. The name of the host to connect to, if different from the alias you wish to give to it. General for all connections: ansible_host.
Non-SSH based types are described in the next section. Free X server for Windows with tabbed SSH terminal, telnet, RDP, VNC, Xdmcp, Mosh and X11-forwarding.Vendor: Model: Version: Access Type: Username: PASSWORD: Privileges: Notes: 3COM: CoreBuilder: 7000/6000/3500/2500: Telnet: debug: synnet: 3COM: CoreBuilder: 7000.Fabric users may also be interested in two strictly optional libraries which implement best-practice user-level code: Invocations (Invoke-only, locally-focused CLI tasks) and Patchwork (remote-friendly, typically shell-command-focused, utility functions).