How to assign a specific DNS server (Adblock) to just one port of the router (for smart TV)

I am setting up a router for my parents which already has OpenWRT 22.03.5 on it. They have a Samsung smart TV that I have isolated with a VLAN and separate interface. I want to assign Adblock DNS to just the TV while having the other devices use another DNS. I have configured the WAN interface to use the preferred DNS but want to confirm how to assign the Adblock DNS to the TV. Do I enter the Adblock DNS in the isolated interface DNS field?

How about binding the adblock dns to the OpenWrt IP of the isolated interface IP only?