How to handle subdomains

[AeonSolstice]

Summary

I want to handle api.my.domain and all.my.domain separately from my.domain. I tried using Host extractor but nothing worked. I looked into the wildcard path routing but the docs are so obscure about that.

Paths can end in /*key which matches all segments and will store the segments captured at key.

Store where? "Captured at key" - what does that even mean?
Then I found https://github.com/tokio-rs/axum/blob/main/axum/src/docs/routing/route.md where a new syntax was being used?

/{*key}

Any why does wildcard not handle /?
Furthermore, any code that I did get to compile silently sent an error as the http body, and was not helpful in any way.

The only discussion I found regarding axum and subdomains had a non working solution, not to mention "use reverse proxy" "use nginx" "dont handle that with axum" "use loadbalancer" "dont do it like this"

I do not want to do any of that. I just want to handle subdomains in rust code directly. Any help besides "use nginx" is appreciated.

If this sounds like a rant, it is probably because I come from a nodejs + express background.

axum version

=0.7.9