Disclaimer
Well, it actually isn’t related to i3 WM, i3 WM is just a window manager, it means it just adjust windows on your screen and that’s it. However, a lot of i3 WM users use dmenu as applications menu
1 - Create a symbolic link to /usr/bin
dmenu just show executables that are on /usr/bin so what we need to do is create a symbolic link to our application to there
1
sudo ln -s /your_app_path/executable /usr/bin/the_name_you_want_to_be_displayed_at_dmenu