Huh I brew installed it and got a working tunnel in like 15 seconds.
The product is falsely advertised as is:
"Cloudflare Quick Tunnels"
This is on one (or two) particular domain(s) where setting up wildcard DNS should be relatively trivial, if they actually cared enough about the UX of this product to make a special case in their code.
I don't understand how people can launch stuff like this.
It's "free". That's all you need to understand.