/etc/pacman.conf
```
[nyyu]
Server = https://archlinux.nyyu.dev/nyyu
```

Import key
```
sudo pacman-key --recv-key 81936FB8BD44A0B8C28CD6B48B9B775C6DAB103E --keyserver hkp://keyserver.ubuntu.com
sudo pacman-key --lsign-key 81936FB8BD44A0B8C28CD6B48B9B775C6DAB103E
```