How to configure site search in GA App+Web property?

In your GA Property Settings, click on Data Streams(BETA). Select the correct web data stream, and click on the edit icon of ‘Enhanced measurement’. On the right-hand panel, you can see all the enhanced measurement settings. Make sure the toggle for ‘Site search’ is on. Click on the cog – ‘Show advanced settings’, update ‘Search Term Query Parameter’ and ‘Additional Query Parameters’ fields and save changes.

How do we find site search reports?

Unfortunately, this is currently not available in App + Web.