Do you have AI Search setup enabled? The ootb AI Search - Fallback topic should cover you without any extra development effort - by default, it's setup to search catalog items and knowledge articles and if you want to adjust its search results, you can implement Result Improvement Rules, i.e. to put a higher weight on catalog items. I believe that screenshot is just using the AI Search Fallback.
If you don't use AI Search, it's more or less the same for the end user, but the topic will be Search Fallback Topic and it uses Contextual Search instead.
Keep in mind, this is intended as a fallback which means that it'll trigger this search if the utterance does not match any existing topic. If somebody types something generic, like "I want to request something", that's not gonna be helpful for your search fallback so you may want to consider having a "Request Catalog Item" topic for that, which you can do super simply by plugging in the ootb topic blocks Search Catalog Item and Request Catalog Item.
