If you use stuff like Ngrok or Zrok to give a external access to some random localhost app you're developing in whatever language and frameworks of your choice and you're sick of its lack of personalisation, this post is for you.
I'm going to save you money and make your dev-life simpler.
Enjoy!
https://maikel.dev/using-haproxy-for-ngrok-style-domain-tunneling-in-nixos-with-ssl-self-renewal-enabled/