Please note that this will install the latest development build. This may be unstable but in my experience it it working fine.
Keep in mind that this will not install the program like on a officially supported distribution. You need to manually update it if there is a new version!
I hope that they will distribute a Snap/Flatpak/AppImage in the future so that the installation will be easier and it will be simpler to update.
If something does not work later there may be new dependencies
(See https://github.com/Ulauncher/Ulauncher#setup-development-environment)
sudo eopkg it git docker yarn pip keybinder keybinder-devel libgtk-3 libgtk-3-devel libwebkit-gtk libwebkit-gtk-devel glib2 glib2-devel libnotify libnotify-devel notify-python notify-python-devel eog-devel libappindicator libappindicator-devel python3-dbus python-levenshtein python-websocket-client pyxdg python-mock python-pytest python-pytest-mock pylint python-mypy python-mypy_extensions python-distutils-extra
cd ~
git clone https://github.com/Ulauncher/Ulauncher.git
cd ULauncher
./ul init-dev-env
./ul build-preferences
./ul run
Now everything should work fine. If the keybind does not work you can set a keyboard shortcut in your corresponding desktop environment settings to execute the command ulauncher-toggle