Add subdomain to nginx and update with https

Flow

sudo certbot --authenticator webroot --installer nginx
select number
add webroot (path/to/app)
sudo service nginx restart

subdomain.example.com

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

server {
   listen 443 ssl;
   server_name subdomain.example.com;

   root   /home/path/to/app;
   index  index.html index.htm;

   ssl_certificate /etc/letsencrypt/live/subdomain.example.com/fullchain.pem;
   ssl_certificate_key /etc/letsencrypt/live/subdomain.example.com/privkey.pem;
}