Ubuntu let's encryt nginx

Wild certificate

sudo certbot certonly --manual --preferred-challenges=dns -d *.fn.quillgen.com

To verify: https://toolbox.googleapps.com/apps/dig/#TXT/_acme-challenge.fn.quillgen.com

Nginx config

server {
    listen 443 ssl;
    server_name ~^(.*)\.fn\.quillgen\.com$;

    ssl_certificate /etc/letsencrypt/live/fn.quillgen.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/fn.quillgen.com/privkey.pem;

    location / {
        proxy_pass http://172.20.0.0;
        # otherwise got 426 Upgrade Required error
	    proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        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;
    }
}

# Redirect HTTP to HTTPS
server {
    listen 80;
    server_name ~^(.*)\.fn\.quillgen\.com$;
    return 301 https://$host$request_uri;
}