Nginxをリバースプロキシサーバとして使う際に、Basic認証を設定したい

server {
    listen 80;
    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;

    # APIルートはLaravelに振り分け
    location /api/ {
        proxy_pass http://laravel:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Requested-With $http_x_requested_with;
    }

    # Laravel SanctumのCSRFトークン取得エンドポイント
    location /sanctum/csrf-cookie {
        proxy_pass http://laravel:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Requested-With $http_x_requested_with;
    }

    # その他のリクエストはNext.jsに振り分け
    location / {
        proxy_pass http://frontend:3000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        
        # WebSocketサポート（Next.jsのHMR用）
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

    auth_basic "Restricted";
    auth_basic_user_file /etc/nginx/conf.d/.htpasswd;

docker logs --tail=100 -f nginx_server
2025/09/07 13:28:52 [error] 29#29: *11 open() "/etc/nginx/conf.d/.htpasswd" failed (2: No such file or directory), client: 172.18.0.1, server: , request: "GET /favicon.ico HTTP/1.1", host: "localhost", referrer: "http://localhost/"

  # Nginx Web Server
  nginx:
    image: nginx:alpine
    container_name: nginx_server
    restart: unless-stopped
    ports:
      - "80:80"
    volumes:
      - ./:/var/www
      - ./docker/nginx/default.conf:/etc/nginx/conf.d/default.conf
      - ./docker/nginx/.htpasswd:/etc/nginx/conf.d/.htpasswd:ro
    networks:
      - app-network
    depends_on:
      - laravel

docker compose up nginx --build

docker exec -it nginx_server /bin/sh
/ # ls -la /etc/nginx/conf.d/
total 20
drwxr-xr-x    1 root     root          4096 Sep  7 13:31 .
drwxr-xr-x    1 root     root          4096 Aug 13 20:42 ..
-rw-r--r--    1 root     root            44 Sep  7 13:01 .htpasswd
-rw-r--r--    1 root     root          1522 Sep  7 13:33 default.conf