If you do not have the two packages installed, issue this command in a terminal window… 
sudo pacman -Syu qt5ct kvantum-qt5
Then, you should be able to start those applications from an application launcher menu ─ sorry, I have no experience with Awesome ─ or from a terminal.
Note: kvantum-qt5 is a theme manager that uses special themes made with scalable vector graphics. In order to use it, you must set the Qt theme in qt5ct to “kvantum” and then load a suitable theme into kvantum-qt5 by pointing it at the directory (“folder”) where you have unpacked the theme.