Issue with resolver in kong running in AKS

We are trying to use plugin GitHub - anup-krai/kong-plugin-set-dynamic-target-host
and set upstream host based on value from one of the request parameter. We are getting below error
when we make a request to the kong.
Is this something to do with kong resolver we tried setting KONG_DNS_RESOLVER pointing it to coredns svc but still getting same are we missing something

2022/02/22 17:23:34 [error] 1102#0: *65257 no resolver defined to resolve kong_upstream<DNS>, client:, server: kong, request: "GET / HTTP/1.1", host: "<DNS>"

You’ll want to post in the General forum here or in Discussions · Kong/kong · GitHub and/or file an issue with the plugin author. This doesn’t appear to be a Kubernetes issue.

Kong uses a Lua DNS client to handle some features that the standard NGINX implementation does not. It does so by creating an NGINX upstream and filling some details in at request time.

The error you’re seeing is from NGINX rather than Kong, which suggests that something that should have happened when the Kong balancer filled in request time details did not happen, and we didn’t populate the NGINX configuration properly. Offhand I don’t spot any obvious issues with the plugin, since it’s using a PDK function to control the balancer behavior, and that should work fine.