Physical Printer

Install and configure CUPS with

sudo apt install cups
sudo usermod -a -G lpadmin pi
sudo cupsctl --remote-admin

Allow access to the CUPS web interface independently from its host name with

sudo nano /etc/cups/cupsd.conf

Add the line below, then save and exit.

ServerAlias *

Reboot with

sudo reboot

Use the CUPS web interface at http://<apple2>:631/ to add and/or manage your printers - replacing <apple2> with the WiFi IPv4 address of the RPi (the one you connect to with the SSH client).

List available printers with

lpstat -p

Set the default printer with the command below - replacing <printer> with the name of an available printer

lpoptions -d <printer>

Now you can print <my_file> with

lp <my_file>