Some of you use ssh in the shell, but this does not work with elementary on a Tuxedo-Laptop. I tried to find the status of ssh, but this doesn' t show either. I tried to install putty - no success. Could it be a deeper problem? Any ideas?
Make sure you got the right connection information. This is not a system error.
More information about SSH and how to use it: https://wiki.archlinux.org/index.php/Secure_Shell#Client_usage (ArchLinux wiki. Excellent documentation)
If you need to add a PublicKey to connect (As the error message suggest) and you're unaware of it, you should try contacting your hosting provider for support.