This members-only tutorial provides the steps to register a custom condition to be applied on elements inside an Oxygen Template that applies to search results.
The condition lets us conditionally output elements depending on whether there is at least one search result or not.
To set this up, you would move everything inside the Template for search results from the other tutorial inside a Div and set this condition on that Div:
After that you would create another Div alongside (at the same level as) the earlier Div and add Heading/Text/Search Form telling the user that there are no results for the term they searched for. Then you'd apply the condition on this Div like so: