Use Pi-Hole in different subnet

[multiforme]

I am on OpenWrt 19.07.2. I have a LAN interface (192.168.1.1/24) that I use for all my devices, and a Guest interface (192.168.2.1/24) for everything else.

These are the zones I configured:

All clients that use the Guest Wi-Fi (there are 2 separate SSID, each on a different radio) are isolated and assigned the Guest interface.

I have a Pi-Hole in the non-Guest subnet (192.168.1.6). How can I forward DNS requests from the Guest subnet to the Pi-Hole?
Is this via Network - Static routes?

Thanks

[trendy]

In /etc/config/dhcp :

config dhcp 'guest'
[..]
        list dhcp_option '6,192.168.1.6'

in /etc/config/firewall:

config rule
        option target 'ACCEPT'
        option dest_port '53'
        option proto 'udp'
        option src 'GuestZone'
        option family 'ipv4'
        option dest 'lan'
        option name 'Allow-guest-pihole'
        list dest_ip '192.168.1.6'

[multiforme]

@trendy

option target 'ACCEPT' option dest_port '53' option proto 'udp' option src 'GuestZone' option family 'ipv4' option dest 'lan' option name 'Allow-guest-pihole' list dest_ip '192.168.1.6'

Thanks! Worked perfectly