Install Keymon

 cd ~/Downloads
dhwan@dhwan-Aspire-A514:~/Downloads$ wget http://archive.ubuntu.com/ubuntu/pool/universe/p/pygtk/python-gtk2_2.24.0-5.1ubuntu2_amd64.deb
--2020-09-24 15:08:31--  http://archive.ubuntu.com/ubuntu/pool/universe/p/pygtk/python-gtk2_2.24.0-5.1ubuntu2_amd64.deb
Resolving archive.ubuntu.com (archive.ubuntu.com)... 91.189.88.152, 91.189.88.142, 2001:67c:1562::18, ...
Connecting to archive.ubuntu.com (archive.ubuntu.com)|91.189.88.152|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 619344 (605K) [application/x-debian-package]
Saving to: ‘python-gtk2_2.24.0-5.1ubuntu2_amd64.deb’

python-gtk2_2.24.0- 100%[===================>] 604,83K   355KB/s    in 1,7s    

2020-09-24 15:08:34 (355 KB/s) - ‘python-gtk2_2.24.0-5.1ubuntu2_amd64.deb’ saved [619344/619344]

dhwan@dhwan-Aspire-A514:~/Downloads$ wget http://archive.ubuntu.com/ubuntu/pool/universe/k/key-mon/key-mon_1.17-1ubuntu1_all.deb
--2020-09-24 15:08:47--  http://archive.ubuntu.com/ubuntu/pool/universe/k/key-mon/key-mon_1.17-1ubuntu1_all.deb
Resolving archive.ubuntu.com (archive.ubuntu.com)... 91.189.88.142, 91.189.88.152, 2001:67c:1360:8001::24, ...
Connecting to archive.ubuntu.com (archive.ubuntu.com)|91.189.88.142|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 85160 (83K) [application/x-debian-package]
Saving to: ‘key-mon_1.17-1ubuntu1_all.deb’

key-mon_1.17-1ubunt 100%[===================>]  83,16K   130KB/s    in 0,6s    

2020-09-24 15:08:49 (130 KB/s) - ‘key-mon_1.17-1ubuntu1_all.deb’ saved [85160/85160]

dhwan@dhwan-Aspire-A514:~/Downloads$ sudo apt-get install ./python-gtk2_2.24.0-5.1ubuntu2_amd64.deb ./key-mon_1.17-1ubuntu1_all.deb
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'python-gtk2' instead of './python-gtk2_2.24.0-5.1ubuntu2_amd64.deb'
Note, selecting 'key-mon' instead of './key-mon_1.17-1ubuntu1_all.deb'
The following packages were automatically installed and are no longer required:
  gir1.2-gmenu-3.0 gir1.2-handy-0.0 gnome-shell-extension-prefs gnome-tweaks
  libayatana-appindicator3-1 libayatana-indicator3-7 libgpaste11
  libhandy-0.0-0 libxdo3 xdotool
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
  python-cairo python-gobject-2 python-is-python2
Suggested packages:
  python-gobject-2-dbg python-gtk2-doc
The following NEW packages will be installed:
  key-mon python-cairo python-gobject-2 python-gtk2 python-is-python2
0 upgraded, 5 newly installed, 0 to remove and 49 not upgraded.
Need to get 241 kB/946 kB of archives.
After this operation, 7.438 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 /home/dhwan/Downloads/python-gtk2_2.24.0-5.1ubuntu2_amd64.deb python-gtk2 amd64 2.24.0-5.1ubuntu2 [619 kB]
Get:2 /home/dhwan/Downloads/key-mon_1.17-1ubuntu1_all.deb key-mon all 1.17-1ubuntu1 [85,2 kB]
Get:3 http://kambing.ui.ac.id/ubuntu focal/universe amd64 python-cairo amd64 1.16.2-2ubuntu2 [57,1 kB]
Get:4 http://kambing.ui.ac.id/ubuntu focal/universe amd64 python-gobject-2 amd64 2.28.6-14ubuntu1 [182 kB]
Get:5 http://kambing.ui.ac.id/ubuntu focal/universe amd64 python-is-python2 all 2.7.17-4 [2.496 B]
Fetched 241 kB in 1s (168 kB/s)              
Selecting previously unselected package python-cairo:amd64.
(Reading database ... 451303 files and directories currently installed.)
Preparing to unpack .../python-cairo_1.16.2-2ubuntu2_amd64.deb ...
Unpacking python-cairo:amd64 (1.16.2-2ubuntu2) ...
Selecting previously unselected package python-gobject-2.
Preparing to unpack .../python-gobject-2_2.28.6-14ubuntu1_amd64.deb ...
Unpacking python-gobject-2 (2.28.6-14ubuntu1) ...
Selecting previously unselected package python-is-python2.
Preparing to unpack .../python-is-python2_2.7.17-4_all.deb ...
Unpacking python-is-python2 (2.7.17-4) ...
Selecting previously unselected package python-gtk2.
Preparing to unpack .../python-gtk2_2.24.0-5.1ubuntu2_amd64.deb ...
Unpacking python-gtk2 (2.24.0-5.1ubuntu2) ...
Selecting previously unselected package key-mon.
Preparing to unpack .../key-mon_1.17-1ubuntu1_all.deb ...
Unpacking key-mon (1.17-1ubuntu1) ...
Setting up python-gobject-2 (2.28.6-14ubuntu1) ...
Setting up python-cairo:amd64 (1.16.2-2ubuntu2) ...
Setting up python-is-python2 (2.7.17-4) ...
Setting up python-gtk2 (2.24.0-5.1ubuntu2) ...
Setting up key-mon (1.17-1ubuntu1) ...
Processing triggers for desktop-file-utils (0.24-1ubuntu3) ...
Processing triggers for mime-support (3.64ubuntu1) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu1) ...
Processing triggers for libc-bin (2.31-0ubuntu9) ...
Processing triggers for man-db (2.9.1-1) ...
Processing triggers for bamfdaemon (0.5.3+18.04.20180207.2-0ubuntu2) ...
Rebuilding /usr/share/applications/bamf-2.index...