How does Apple CarPlay work when making phone calls and going to a prompt menu?

I cannot find a way when my iPhone is connected in Apple CarPlay to respond to a prompt menu asking you to press #1 for xyz or press #2 for abc. I've only been able to do it by manually pressing the number on the dial menu on the iPhone. Which means I'm physically having to manipulate my iPhone, not good when driving. I have a voice app that I use for all my business calls from a well known company that rhymes with doodle and which forwards all calls to my iPhone where I have to press #1 to accept. Obviously this problem spans all set of calls, i.e. to Call Centers, reaching specific people at a business etc.

I'm beginning to believe that this is a feature that does not exist and my solution while poor is the only way to make it work.