This user is using AI to write short sentence spam. And he is trying to claim my code in the process:

Profile: GHOST Buster (I guess that username is fitting)

--snip--

I don't know if code falls into the category of plagiarism, and I did not explicitly put a license like Modified-BSD that prevents people from claiming others' work as own, but this is very scumbag behavior.

But the explanation of the code is also wrong, so it should be removed immediately regardless

You're under no obligation to choose a license. However, without a license, the default copyright laws apply, meaning that you retain all rights to your source code and no one may reproduce, distribute, or create derivative works from your work.