Can I use a writing prompt to publish a book?

I found a good writing prompt and I've written a couple chapters for a book I want to publish, but now I wonder if that's a good idea or not.

Just don't copy it exactly, because otherwise people could connect your book to the prompt.

Like @Masterkey said, don't copy it. I'd also advise altering the wording if it's a dialogue prompt and changing more details if it's a description one. If it's just a story prompt, that's a little different. You might want to consider adding more unique details to the actual storyline to separate it from just that one prompt. Otherwise, it's less of your own story and more of a slightly tweaked version of their idea.