server {
    listen 80;
    server_name dsm.username.synology.me;

    return 301 https://$host$request_uri;
}

# For ssl
server {
    client_max_body_size 8M;

    ssl on;
    ssl_certificate /etc/letsencrypt/live/dsm.username.synology.me/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/dsm.username.synology.me/privkey.pem;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;
    ssl_dhparam /etc/ssl/certs/dhparam.pem;
    ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GC$
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_stapling on;
    ssl_stapling_verify on;
    add_header Strict-Transport-Security max-age=15768000;
    default_type  application/octet-stream;

    listen 443;
    server_name dsm.username.synology.me;

    root /var/www/dsm;

    location ~ /.well-known {
        allow all;
    }

    location / {
        proxy_pass https://192.168.1.xx:5001;
    }
}

sudo certbot certonly -a webroot --webroot-path=/var/www/dsm -d dsm.username.synology.me