How to schedule pre-PMF sales call ? I will not promote

I have recently started looking at B2B SaaS and reading online the top advice is to schedule pre-PMF sales calls with potential customers and figure out the pain points. But I am not sure what to actually say in a cold email. Nobody wants to do an interview about their pain points and if I do a call without the product it would seem somewhat deceptive (won't seem like a sales call but a survey call). Do you guys have some suggestions on how to go about doing this, or a rough template for this cold email ?