TapTechNews July 6th, the source @PhantomOfEarth tweeted yesterday (July 5th) that after the Microsoft Store was updated to the latest 22406.1401.1.0, a search box was finally added in the Library.
TapTechNews note: Microsoft currently only invites a small number of Windows Insider members to test, and even if users upgrade to the latest version, they may not be able to see this search box. Users now don't need to scroll or use the search of the main application store, but can directly search for applications or games in the Library.