Support LTS(wireguard-lts) and not official support kernels (wireguard-dkms, for Hardened and Zen kernel's too)
First upgrade system & reboot
pacman -Syu
reboot
After download script
wget -q https://raw.githubusercontent.com/L1LjSHX/wireguard_archlinux_server/master/wireguard_install.sh
Or just clone repo... For install run:
chmod +x ./wireguard_install.sh install
For remove
./wireguard_install.sh remove
And add client
./wireguard_install.sh add