xclip is required. (install with sudo pacman -S xclip for arch)
xclip
sudo pacman -S xclip
for memory & cpu load in tmux's status bar tmux-mem-cpu-load is required. (install with paru -S tmux-mem-cpu-load for arch from AUR)
tmux-mem-cpu-load
paru -S tmux-mem-cpu-load