I thought the "written by human not AI" badge was kind of cute, then I clicked on it. It seems like people pay for the "right" to put that badge on their page? The author was scammed.
EDIT: So the payment is to have a little space on their own website, which they call a "project page" e.g. https://notbyai.fyi/hi/not-by-ai/
They suggest "linking to it for verification", but it really seems both unnecessary and optional