Deploying my web app (Nginx, Gunicorn, Django) on Ubuntu 16.10 I get a 403 error when clients try to load files to the server. Files are supposed to be saved in /var/www/annotator/media/dmitrybaranchuk/

I've read a lot of topics about the similar issues however nothing helped. I'm almost positive this is the problem with nginx / permissions / users. Maybe someone knows how I can fix this issue. The main information is below.

Error Logs

• Safari Web Inspector:
  [Error] Failed to load resource: the server responded with a status of 403 (Forbidden) (dmitrybaranchuk, line 0)

• nginx-error.log:
  [error] 10713#10713: *5 directory index of "/var/www/annotator/media/dmitrybaranchuk/" is forbidden, client: 31.173.80.174, server: 138.197.16.71, request: "POST /media/dmitrybaranchuk/ HTTP/1.1", host: "138.197.16.71", referrer: "http://138.197.16.71/"

• /var/log/nginx/error.log: empty

Info

• Nginx processes:
  root - master process /usr/sbin/nginx -g daemon on; master_process on;
  www-data - worker process

• /var/www permissions:
  /var/www and every directory/file inside has permission: 777, user: www-data, group: www-data.

• SELinux: Disabled

• /etc/nginx/sites-enabled/annotator

  server {
  listen 80;
  server_name 138.197.16.71;
  access_log /home/dmitrybaranchuk/pose_annotator/logs/nginx-access.log;
  error_log /home/dmitrybaranchuk/pose_annotator/logs/nginx-error.log;
  
  location /static/ {
      alias /home/dmitrybaranchuk/pose_annotator/static/;
      expires 30d;
  }
  location /media/ {
      alias /var/www/annotator/media/;
  }
  location / {
      autoindex on;
      proxy_pass http://127.0.0.1:8000;
      proxy_set_header Host $host;
      proxy_set_header   X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }
  }
  

• /etc/nginx/nginx.conf

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
        worker_connections 768;
}

http {
        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        gzip on;
        gzip_disable "msie6";

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}