@Alex, looks like copying the code in your screenshot directly from this article might copy 'smart quotes' instead of 'straight quotes'. That's what it looks like in your screenshot and that's how it's working for me.

Try deleting each smart quote in what you've copied into the JS part of your Help Center code, replace those with straight quotes, and that should do it.

Here's a video I recorded showing me previewing the Search input field before/after my suggestion.

Give it a try.

Update | This article has been updated so copying the code directly from this article now will be copying straight quotes instead of smart quotes.

-Jeremiah

Application Engineer, Zendesk