Why does the site not work through ipv6 (502, nginx)?

Question

Nginx

Hello.
I added AAAA records for the domain, configured the nginx web server as follows:

server {
  listen [::]:80 ipv6only=on;
  listen 80;

  server_name example.com www.example.com;

  root /var/www/default;

  location / {
    try_files $uri $uri/ =404;
  }
}

But the site still does not work, it gives an error 502. Hosters say that I have not added an address to the server, but I don’t quite understand where to add it, I’m setting up ipv6 for the first time.