When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make easier to read.
See this post to find the backtick on your keyboard. The “preformatted text” tool in the editor (</>) will also add backticks around text.
It is not possible to test if you used the rest operator other than checking what you have written, as such it is not possible to let users use any name parameter they want - so the challenge asks you a specific parameter name