Enable dead key usage in urxvt
Solution 1:
I have the English US keyboard, and I switch to the English US International keyboard with dead keys to type accents in Spanish. I have no issue typing accents in urxvt. I am using Debian 11.
To set my keyboard, I can use the commands:
setxkbmap us
setxkbmap us intl
Furthermore, I have a keybinding set to run this script to toggle between keyboard layouts:
#!/bin/bash
setxkbmap -query | grep -q "variant" &&
(setxkbmap us && notify-send -t 400 "Keyboard US") ||
(setxkbmap us intl && notify-send -t 400 "Keyboard US International")