I'm building a reading game and I want to run simple ethical ads for fantasy novels and live play RPG podcasts and the ilk on the homepage of my app at a later

I'm building a reading game and I want to run simple ethical ads for fantasy novels and live play RPG podcasts and the ilk on the homepage of my app at a later point. I'm at the point in building where I'm initially building my audience and need to advertise that my game exists to the world. Where else can I buy an ethical ad to find my potential players? My best idea so far has been to purchase an advertisement on some of those podcasts I mentioned, since they are just reading a sentence or three during their normal recording so there is no additional tracking really going on that I'm aware of. You four would be a great option for reaching other developers. Imagine if you could search for ethical advertisers by category with links to reach out. Does this exist already?