https://etedward-gptzero-main-zqgfwb.streamlit.app/
This web app will analyze text and tell you if it thinks a person or AI wrote it. I've tested it with some AI-like writing, and it says it is a human most times, thoguh some it says it is not sure. But feed it AI text and it's pretty good at spotting it.
Enter text in the box, then press ctrl-enter to analyze. It will give you as bunch of info, then you have to scroll to the bottom and hit "get result".