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

I sent 3 messages on a professional network and got two replies. I am in Minneapolis, in case local advice matters. I worry about bothering people. 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.

Follow up with a thank-you and a short update. One of my chats led to a referral a month later.