How to spoof a only a directory of a website (e.g. example.com/spoof) via DNS

DNS Spoofing is considered…bad. But that’s only because people do not use it for good.

I am trying to block a directory of a website by spoofing it on my local DNS server. However, I do not want it to redirect. Here is an example of what I have done so far. The website shall remain unnamed for privacy.

http {
    server {
        listen       80;
        server_name  example.com;
		
		location / {
			proxy_pass http://example.com/;
			proxy_set_header host $http_host;
			resolver 8.8.8.8;
		}
		
		location = /blocked/blocked.json
		root /dns/;
		autoindex on;
    }
}

The directory of the website that I want to block (examp;e.com/iwantthisblocked) passes through the DNS and pulls up what it would without a DNS at all, however, the main directory of the website (example.com) throws a 500 internal server error.

This is running on an Ubuntu server with DNSMasq (DNS is set up properly).