Choosing the correct keymap on IPFire 3 initially would be done on the first boot during the setup wizzard.
If there are any reasons to change the keymap at a later point again this easily can be done by the *localectl command which is part of the used init system systemd.
The current settings can be shown as following:
localectl status
System Locale: LANG=de_DE.UTF-8
LANGUAGE=de_DE:de
VC Keymap: de-latin1-nodeadkeys
X11 Layout: de
X11 Model: pc105
X11 Variant: nodeadkeys
X11 Options: terminate:ctrl_alt_bksp
You safely can ignore all that X11 stuff because we do not own a graphical desktop environment.
To get a list of all supported locales and/or keymaps you can use
localectl list-locales
localectl list-keymaps
And to change to your preferred locale and/or keymap type
localectl set-locale <YOUR PREFERED LOCALE>
localectl set-keymap <YOUR PREFERD KEYMAP>
The changes instantly take effect and are persistent after a reboot.