In the WhatsApp Flows best practices guide, it is said to make sure validation rules are clearly communicated to the users (attachment). It presents an image with a name and phone number input fields with validation. My question is: is it even possible to do that? I checked the WhatsApp Flows docs and found only very simple validation with the "input-type" parameter. Is there anything I'm missing?

If it is indeed possible, I'd be very grateful if anyone could show an example.