Trying to setup custom domain forwarding in a .conf file

[Bucking_Horn]

@drjarmin

I'm trying to set up custom domain forwarding. To test the rule is working, I created:
(…)
address=/google.com/0.0.0.0

That's not forwarding - rather, that would instruct Pi-hole to answer A requests ending in the label google.com with 0.0.0.0.

@drjarmin

which also didn't work so tried:
server=/google.com/0.0.0.0

That's forwarding, instructing Pi-hole to forward resolution for domains ending in google.com to 0.0.0.0, but 0.0.0.0 likely wouldn't know heck about DNS.
You'd usually pick a public DNS server IP as forward target, or another local DNS server IP.

@drjarmin

Any pointers on why my approach isn't working here?

Pi-hole v6 doesn't read /etc/dnsmasq.d/ by default, see Custom dnsmasq configs not loading.

Either enable misc.etc_dnsmasq_d, or instead -for a few lines- add them directly to misc.dnsmasq_lines, as as accessible via Settings | All settings » Miscellaneous .
All settings is available in Expert mode only.