During the Debian installation process, we are prompted to set up our keyboard layout and distribution. Unfortunately, my preferred layout is not listed as one of the available options.
I would like to set it up as English International with AltGr dead keys.
This is something I need to configure as a post-installation setting by running the following command:
su -c 'localectl set-x11-keymap us thinkpad altgr-intl'
This sets the layout to English (US), the model to one compatible with my Lenovo ThinkPad T440p, and the variant to Dead keys via AltGr. This allows me to input characters such as á or ñ by simply pressing: AltGr + a or AltGr + n, respectively.
pionen@lilit:~$ localectl
System Locale: LANG=en_US.UTF-8
LANGUAGE=en_US:en
VC Keymap: n/a
X11 Layout: us
X11 Model: thinkpad
X11 Variant: altgr-intl
This way, I can continue using the English (US) keyboard layout when typing in either English or Spanish without needing to change the variant or physical layout.