Do you understand what plagiarism is? You plagiarize when you make someone's or something's content appear as if it were your own. If you deliberately omit the source of presented content when it isn't yours, you plagiarize.

Doesn't matter if its a bot or copied from a website or chatbot prompt output. Doesn't matter if you have a browser extension that talks to ChatGPT or whatever behind the scenes. If it generates text that you wouldn't have come up on your own, it's not your content. Don't make it look like it is your own content, to be safe always provide a source reference.