to instal add-module ghcr.io/stephdl/pihole:1.0.0-dev.2
a test is done to prevent the configuration if the 53 ports are used by other module, no way, install pihole on another node
then you can configure a vhost with a password and optional dns server
normally the port 53 is opened to outside, you can test locally by querying host google.com 127.0.0.1 or from external (change 127.0.0.1)
to use pihole set by dhcp the ns8 as the dhcp server of your network, if you need it you can set optional dns to use for example samba AD if needed.