How do I ask for an informational chat? - any advice?

I want to talk to people in a new field but I hate cold messages. I would rather hear the honest version than the polite one. Some people reply with short answers. How do you phrase the request?

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.

Do not apologise for asking. Most people remember someone who helped them.