This is a primarily large company focused initiative. You’ll need to work with apples partner integration chat providers to build on it. It’s invite only at this point.
Setting up WhatsApp business is far easier. Cannot work out at all how to use this. Seems if you’re a big company dw Apple will come to you.
They keep announcing this as if it's a new thing but it has been in beta for a couple of years. If/when they are serious about this being a real communication channel between companies and customers they should provide a simple API and registration process like Twilio.
The idea seems cool, but finding information on how to get setup as a company with business chat has proved somewhat elusive for me.