How can I install zapret dpi on arch linux

The title says it all

zapret is in the AUR https://aur.archlinux.org/packages?K=zapret (zapret-nfqws-git)
then follow these instructions (skipping the clone/compile/copy step, of course).
the second instruction is more detailed
https://github.com/yt-dlp/yt-dlp/issues/10443#issuecomment-2248940967
https://ntc.party/t/goodbyedpi-4-linux-ubuntu/8394/6

Aur is full of viruses and unchecked software “maintained” by randos. Using aur is as risky as downloading from random site. Never use aur on any of the arch based distros

So use wireguard+nmap from repository.