How do you promote something you have built for fun without paying for ads?

I would like to tell developers about something I have built. Every time I write a content that slightly mentions it, it gets flagged and removed immediately. I've tried posting articles on multiple platforms and subreddits. The content does fine on its own but the moment I mention my project it gets killed. As of now, my platform/tool is completely free and I want to keep it that way. I've built it for fun, as a hobby, not as a business so I don't want to have to run paid ads because that means I would have to charge people to cover the costs. So my question is, what do you guys to to get the word out about your projects without spending money on ads?