Built StudyLoop, live, $0 revenue - what got you your first users?

I shipped StudyLoop about a month ago. It turns your notes into spaced repetition review sessions automatically instead of making you build flashcards by hand. Revenue so far is exactly zero dollars, and I'm trying to figure out if that's a marketing problem or a nobody-actually-wants-this problem.

I've posted a couple times in study subreddits and got some downloads, but nobody's converting to the paid tier. I don't know if the pricing is off, the onboarding loses people before they see the value, or I'm just talking to the wrong crowd.

For those of you who got your first ten paying users, what actually worked? Was it one specific channel, cold DMs, posting in a niche community, or something more boring like just asking friends first? I keep reading that you're supposed to talk to users before building, and I did some of that, but clearly not enough or not the right way.

Happy to take blunt feedback here too if anyone wants to poke at the actual product: https://studyloop-jelonmans-projects.vercel.app. No pressure, just trying to learn from people who've already been through this part.