How do I ask for an informational chat? - what worked for you?

I sent 5 messages on a professional network and got two replies. I have been trying to stay organised about it. 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.

Thanks for writing this out. I went through something close to it 12 months ago, and it got easier once I kept a simple log of every call and form.