Google Analytics 4
The Unique events metric featured in Universal analytics is based on a session model, e.g. how many times an event fired per session.
The App+Web measurement moves from a session-based to user-based model. Therefore, this metric is not available in the reporting interface.
App+Web data is streamed into BigQuery so you could calculate it based around the session_start event if you wanted to see this metric ongoing.
The App+Web properties are based on different measurement model than standard analytics properties.In App+Web properties everything we capture are either event or user scope even sessions and page views. Since we are moving away from session based measurement model we will not have unique events i.e. total number of events per session.
The new property provides events with number of occurrence i.e. count, which is similar to events with total events in standard analytics event reports.
App+Web event report