So any survivors know what to put on your gravestone?

Do you know what a pure function is? Look it up if you don't.
If the solution to this kata were a pure function, it will clearly not work. Therefore...

Yes, and you have to write your function so the argument is optional.

Note: your function should have a default parameter.

That's part of the task. Not a kata issue.

You're asking for feedback and that's what you got, I don't see any hate in the previous comments. I'd add, add random tests, they're mandatory, have you read Kata authoring guide yet? https://docs.codewars.com/authoring