The When Empty Item shows users a message when no results are found from a Loop element’s query. This is useful for giving users further guidance and/or understanding on why they aren’t seeing any results.
To set the When Empty item, you’ll want to go to the Design tab of the Loop element, click the Advanced popout under the applicable area for the Loop element, and then select the Global Block you would like to use for the When Empty condition.
Now, if the Loop doesn’t return any results, the When Empty block will show up.