Basically, you need PCL 5 driver. (PCL 6 will not work).
I saw following video, which helped. It did not work on DOT4_001 port for me, but worked when I installed the printer on USB port.
Saved my old faithful printer from going to a landfill. I am feeling good.
I am trying to set up SFTP access to my site and having problem.
Thankfully I found following link which was useful to set up Public Key Authentication on my GNU/Linux laptop.
I had to generate SSH keys on my server and authorize the public key.
Then I had to download SSH private key to laptop.
Then I had to check whether .ssh directory already existed.
It did not exist, so I had to create it.