The error was in the scope.
I would say that this is strange, because if you run everything single-handedly, then everything goes well.
I have fixed the error, thanks.

I totally agree with you. This is where the work is done in an array within an array. I saw a great solution here via replace and regExp

Before clicking that the problem has been solved, you need to check the code. Everything is written very clearly here that the code with the wrong test is expected. P.S for MikChan(expected is an expectation from your test and it is not correct. since the first character must be uppercase)

Are you laughing? My code will return the correct value 'ZtK AuWyK Dy HqV'
(it also says that he was just expecting the meaning of the first character with a small letter)