Error redirecting prometheus call with nginx

Why am I getting 404 error after authenticating to the call http://<ip-external>:80?

I would like when the call was made, he authenticated with username and password, and it was returned after the page of prometheus

docker.compose.yml

version: '3.1'

services:
  prometheus:
    image: prom/prometheus
    container_name: meta_prometheus
    user: '0'
    volumes:
      - /etc/prometheus:/etc/prometheus
      - /prometheus/data:/prometheus/data
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
      - '--storage.tsdb.path=/prometheus/data'
    ports:
      - 9090:9090
    network_mode: host

nginx.conf

pid        /etc/nginx/logs/nginx.pid;

http {
  server {
    listen 0.0.0.0:80;
    location / { 
      proxy_pass http://localhost:9090/;

      auth_basic "Prometheus";
      auth_basic_user_file ".htpasswd";
    }
  }
}
events {
}

returned

enter image description here

Ref: https://www.robustperception.io/adding-basic-auth-to-prometheus-with-nginx

Nginx version: 1.9

OS: Red Hat Enterprise Linux 7.9

Source: Docker Questions