Formerly Key Mapper

An easy to use tool to change the mapping of your input device buttons.
Supports mice, keyboards, gamepads, X11, Wayland, combined buttons and programmable macros.
Allows mapping non-keyboard events (click, joystick, wheel) to keys of keyboard devices.

Usage - Macros - Installation - Development - Screenshots - Examples

pacaur -S input-remapper-git

Get a .deb file from the release page or install the latest changes via:

sudo apt install git python3-setuptools gettext
git clone https://github.com/sezanzeb/input-remapper.git
cd input-remapper && ./scripts/build.sh
sudo apt install ./dist/input-remapper-1.3.0.deb

input-remapper is now part of Debian Unstable

Dependencies from your distros repo: gtksourceview4

sudo pip uninstall key-mapper
sudo pip install --no-binary :all: git+https://github.com/sezanzeb/input-remapper.git
sudo systemctl enable input-remapper
sudo systemctl restart input-remapper

If it doesn't seem to install, you can also try sudo python3 setup.py install