server {
  listen      80;
  server_name example.com;
  return 301 https://example.com$request_uri;
}

server {
    listen       443 ssl http2;
    (中略)
    ssl_certificate      /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key  /etc/letsencrypt/live/example.com/privkey.pem;
}