The best way is to just follow what I do in this video.
Just know that this application is called xfce4-panel-profiles.
Starting from 18.10 the newer package and its configuration are already installed.
If you want to keep rolling and do not do a clean install then …
Install both these packages
sudo pacman -S arcolinux-xfce4-panel-profiles-git
yay -S xfce4-panel-profiles
The old application has to go now.
sudo pacman -R xfpanel-switch