I think I know how to do it.
Now with iptables I redirect port 80 to 3000. I should add a second redirect from port 443 to 3001. 3001 will be a node https server. See:
https://stackoverflow.com/questions/5998694/how-to-create-an-https-server-in-node-js#14272874
That simple server will return a redirect header to use http instead. Maybe it works.