Experienced founders: How do you sell before building? I will not promote

Currently just started going after a problem I’ve experienced for a long time, and it’s a proven problem with heavy demand (B2B sales engagement processes and outbound) (many players around sales engagement platforms, but lacking in properly solving it all) But I’ve identified our differentiator (which isn’t some unicorn, but just a more efficient impressive way to solve the same problem (agentically to an extent), and there’s a big competitor going that route too) I’ve built a clickable prototype that’s quite impressive and ready to demo Now my main question is: The advice I hear now is to start convos with my potential buyers from outreach, ask for advice on the problem to learn more about it, get them to trust me on solving this, then on a 2nd call show them the clickable demo and ask if they’d pay for pilot Ofcourse they must trust me enough that I can solve this But to me I still wanna understand how can execute this where I actually get my ICP to rant about the problem, I show them the demo, and then ask for a contract As I don’t wanna build anything yet before having a full grasp and understanding and working around the problem with a pilot But I’m still not sure how I can go about this now and if this is even the right way to go about it Would love to get your advice if you’re experienced and have succeeded in selling before building before