Can I completely remove the http section from configuration.yaml?

I stil have this http configuration in my configuration.yaml:

#http (for Let's Encrypt on Duckdns.org)
http:
  server_port: 99999
  base_url: https://xxxxxx.duckdns.org:99999
  ssl_certificate: /ssl/fullchain.pem
  ssl_key: /ssl/privkey.pem
  ip_ban_enabled: false
  login_attempts_threshold: 20

I’m planning to move to 100.3 soon, where api password is deprecated. Also, I am now using Nabu Casa for remote access, so I believe I don’t need DuckDNS anymore. My Hassio add-ons all support Ingress.

Can I simply remove the http section entirely? Or do I still need certain lines for some purpose?

You can remove them if you don’t use any of them.