How to write config for dynamic subdomains with node?

Question

Nginx

I have a generated subdomain with node. Example http://5fa70a28cedbc3.21344471.example.com/.

I have written a config for dynamic subdomains without nodes

server {
    server_name *.example.com;

    listen 443 ssl;
    
    root /var/www/platforms/$host;
    index index.php index.html index.htm;

    location / {
        root /var/www/platforms/$host;
        autoindex off;
    }
}

How to write a config for such subdomains?