Giving away EdTech product in exchange for feedback?

I left classroom teaching after 20 years to pursue the entrepreneurial dream. I know the ins and outs of public education and would love to chat if there are any teacher-->startup folks.

Myself and two co-founders are launching an LMS (learning management system). The idea is that everything is in one place - interactive activities, videos, embedded games, simulations, assessments, and more. Normally, teachers would have to have logins, accounts, and content on a dozen sites and apps for what we offer.

We want to launch in the US, but it's nowhere near ready and won't be for sale before next year. That said, we've tried to integrate all the pieces of a good 'classroom operating system' - assignments, grades, interactive video, simulations - and put it all in one place, and let you use content in all of those features without re-creating anything.

Right now, we just need feedback, so we're giving the platform away for free in the US, and all we are asking in return is for folks so tell us what works, what doesn't, what they like, and what features they wish it had. We're really scrappy and can be super responsive.

Our biggest challenge, and where I'd need advice. How to get teachers (who have almost no say over their platform choice) to start using and giving feedback to help us iterate. If anyone has ever had a similar experience, I'd love to hear about it!

I've been a teacher, so I know the structural challenges, but this seems like more of a first-hurdle challenge.

Even if people just use it and don't tell us, it would help us know what users.
It's called Litmus Learn (www.litmuslearn.com)