Input method with GNU Emacs 26.1

[soyeomul@doraji.xyz (Byung-Hee HWANG (황병희, 黃炳熙))]

According to https://www.emacswiki.org/emacs/InputMethods,

#+BEGIN_SRC: text
For X Windows, add the following line to your ~/.Xresources.
    Emacs.useXIM: off
#+END_SRC

However that does not work at GNU Emacs 26 (Actually that worked at GNU
Emacs 23.3).

Is there a hints? 

### my env begins here ###
(bionic)soyeomul@localhost:~$ sudo lsb_release -a
[sudo] password for soyeomul: 
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04 LTS
Release:	18.04
Codename:	bionic
(bionic)soyeomul@localhost:~$ dpkg -l | grep emacs
ii  emacs26                                    26.1~1.git07f8f9b-kk1+18.04         arm64        GNU Emacs editor (with GTK+ user interface)
ii  emacs26-common                             26.1~1.git07f8f9b-kk1+18.04         all          GNU Emacs editor (common files used by Gtk and NoX variants)
ii  emacsen-common                             2.0.8                               all          Common facilities for all emacsen
(bionic)soyeomul@localhost:~$ uname -a
Linux localhost 3.18.0-14597-g61c88fee5b70 #1 SMP PREEMPT Thu Jul 13 12:01:12 PDT 2017 aarch64 aarch64 aarch64 GNU/Linux
### my env ends here ###