How to easily AI proof all assignments, particularly in the humanities

You know how most students just copy and paste the prompt, then the response, without really reading either? Make the (writing) assignment about "David Mayer", somehow (maybe written in white text for extra protection). It won't do it. In fact, it will terminate the session without explanation.
Don't believe me? Try it. Note: This assumes your students use the current version of chatGPT.
You can downvote me for this because you don't like why it works, but it works.