Unit sshd.service could not be found.

This error message suggests that the sshd service is not installed or is not running on the system. To resolve this issue, you can try installing the sshd service using your system's package manager.

For example, on Ubuntu, you can install the sshd service by running the following command:

sudo apt-get install openssh-server

Once the installation is complete, you can start the sshd service using the following command:

sudo systemctl start sshd

You can also configure the sshd service to start automatically at boot time using the following command:

sudo systemctl enable sshd

I hope this helps! Let me know if you have any other questions.