How to install openssh-server on openSUSE

I recently installed openSUSE, and I want to set up an ssh server so that I can ssh into this machine. However, I am having trouble installing openssh-server.

I have tried

$ sudo zypper install openssh-server

But I get this message:

Package 'openssh-server' not found.

How can I install openssh-server on openSUSE? The solution doesn't need to use zypper, but I'd prefer not having to manually download and compile the source code.