How to find Pilot Testers to validate an MVP? - I will not promote

I have successfully built a prototype of a new SaaS/AI tool, but I’m really struggling to get people to pilot test my product and provide feedback. I began by cold messaging about 85 people on LinkedIn; I have a network of over 4000 people (most of whom I don’t know) to message / cold call via DM. So far, I have had only 1 person successfully try my product and meet with me to share their feedback. All the other people who agreed to test (about 6) fell quiet, and never responded after multiple follow-ups. Following the Lean Startup methodology, I don’t want to build anything else until I’ve validated my initial idea, but holy is it hard to get people to even try it. Any suggestions?