Cannot use ibus on applications

I'm trying to install ibus. I changed my environment variable XMODIFIERS to ibus, then I log out and login, the variable still the old one, its doesn't change. I tried unset it and export it again but it still the same. I'm new to Ubuntu so if there're something I need to know, please tell me. I'm very appreciate.

UPDATE: I can change XMODIFIERS with im-config but the ibus only works with the search bar, not working with the applications.

UPDATE_2: I want to use Vietnamese, I turned on the ibus but I'm only able to type Vietnamese on the search bar. When I change to any application like Text Editor, LibreOffice or Browsers,... I cannot type in Vietnamese.

Here is my output for 2 commands below:

env | grep -E 'XMOD|_IM'

GTK_IM_MODULE=ibus
QT4_IM_MODULE=ibus
XMODIFIERS=@im=ibus
CLUTTER_IM_MODULE=ibus
QT_IM_MODULE=ibus



ps aux | grep ibus

tristan+    1831  0.0  0.0   2888   964 ?        Ss   10:58   0:00 sh -c /usr/bin/ibus-daemon --panel disable $([ "$XDG_SESSION_TYPE" = "x11" ] && echo "--xim")
tristan+    1839  0.1  0.1 326544 12256 ?        Sl   10:58   0:00 /usr/bin/ibus-daemon --panel disable
tristan+    1927  0.0  0.0 248852  7700 ?        Sl   10:58   0:00 /usr/libexec/ibus-dconf
tristan+    1931  0.8  0.3 359612 30252 ?        Sl   10:58   0:04 /usr/libexec/ibus-extension-gtk3
tristan+    1937  0.0  0.0 248780  7784 ?        Sl   10:58   0:00 /usr/libexec/ibus-portal
tristan+    2117  0.5  0.1 1300968 9560 ?        Sl   10:58   0:02 /usr/lib/ibus-bamboo/ibus-engine-bamboo --ibus
tristan+    2318  0.0  0.3 206432 24664 ?        Sl   10:58   0:00 /usr/libexec/ibus-x11
tristan+    5896  0.0  0.0  20740  2664 pts/0    S+   11:07   0:00 grep --color=auto ibus

Here is my information:

• My Ubuntu version: Ubuntu 22.04.2 TLS
• Desktop environment: GNOME
• I've tried typing on: Chrome, Firefox, Brave, LibreOffice, TextEditor
• Package: I downloaded ibus with this git repository: https://github.com/BambooEngine/ibus-bamboo#c%C3%A0i-%C4%91%E1%BA%B7t-t%E1%BB%AB-openbuildservice

You didn't provide much information, so I'm going to guess a bit.

On an Ubuntu system you should use im-config to deal with XMODIFIERS and other environment variables which need to be set for ibus. If you have installed ibus, and "something" still changes XMODIFIERS to something else but @im=ibus, the explanation might be that you also have fcitx5 installed and run with some Asian locale.

In that case you can run the im-config command in a terminal window and explicitly tell it to configure ibus for your user. Then reboot.

im-config should both start ibus and set the necessary environment variables at login. So you shouldn't need to bother with those things manually.