nginx auth_request doesn't post :(

nc_api.sh

#!/bin/bash
while true ; do  echo -e "HTTP/1.1 200 OK\n\n $(date)" | nc -l -p 1501  ; done

nc_auth.sh

#!/bin/bash
while true ; do  echo -e "HTTP/1.1 200 OK\n\n $(date)" | nc -l -p 1500  ; done

nginx.conf

server {
    listen       80;
    server_name  localhost;
    
    auth_request /auth;

    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
    }

    location /api {
        proxy_pass "http://127.0.0.1:1501/";
    }

    #error_page  404              /404.html;

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }

    location = /auth {
        internal;
        proxy_pass "http://127.0.0.1:1500/";
        proxy_pass_request_body on;
        proxy_pass_request_headers on;
        proxy_set_header X-Original-URI $request_uri;
        proxy_set_header X-Original-Method $request_method;
        proxy_set_header Host $http_host;
    }

}