How To Display A Search Bar In Google Search Result

After a search in Google, I saw that some website result display also a search bar after their first result where the user can search their website like on the image below Now ple

Solution 1:

You can do it by following the instructions in this page : https://developers.google.com/structured-data/slsb-overview

I think this solves your problem. While it is somehow technical, this is the solution.