How to get right response when use dns

[ssacpklnm]

I used dns in the forward proxy like that:
resolver xxx.svc.cluster.local valid=10s;

As you can see in the title, if I use a forward proxy and dns, when the domain name accessed cannot be resolved, the result returned by the curl command is

User-Agent: curl/7.79.1
Accept: /
Proxy-Connection: Keep-Alive

Mark bundle as not supporting multiuse
< HTTP/1.1 502 Bad Gateway
< Server: nginx
< Date: Mon, 30 Dec 2024 02:35:24 GMT
< Content-Type: text/html
< Content-Length: 150
< Connection: keep-alive
<

How can I get normal echoes when accessing unresolvable domain names with dns and this project?

Expected output：curl: (6) Could not resolve host