matchbox-keyboard-im packages (link for Raspbian, if you have Buster, you need
.deb files version 0.2 dated
28-Jun-2020). Write installation commands in a text file, e.g.:
sudo dpkg -i matchbox*
<- don't forget the newline after the last command
Put the packages and the text file on the FAT partition of the SD card (on the Pi, this will become the
/boot folder), plug the card your Pi zero, open the text file with a text editor, and then copy the commands in a terminal window. If you copy a command with the newline character, it gets executed automatically when you paste it.
I don't recommend
florence, in my experience this keyboard performs poorly in many scenarios.