In short, so to not repeat the others' advice -- yeah, go find communities where those people you think will find this useful hang out. Contributing will not only spread the word, but also help you refine some of your assumptions for sure.

This can be time-consuming, so there's sometimes a tempting direction to try and distance from this process by using marketing automation tools that would post for you, but I would advice against that precisely because there is a lot of value to just be present where your potential users are. Using AI carefully to help you scout the most interesting topics and discussions, though, may be a remedy, and I myself sometimes do that. Good luck!