Important: This printer is a "host-based" printer. It does not work with standard TCP/IP ports or many wireless print servers. You must install the software before plugging in the USB cable.
sudo apt install hplip hp-setup -i Follow prompts. Plug USB when asked. The HP LaserJet 1020 Plus is a tank (great printer), but its driver is old. Once installed, never unplug it from the same USB port or Windows may lose it. Consider keeping a copy of the working .inf driver files on your desktop.