Google Analytics 4

 

https://raddinteractive.com/what-is-the-new-google-analytics-4/

https://developers.google.com/analytics/devguides/collection/protocol/ga4/sending-events?client_type=gtag#required_parameters

https://ga-dev-tools.web.app/ga4/event-builder/

Google Analytics

How To Check Concurrent Visitors With Google Analytics

Session Duration, Avg

http://www.cloudways.com/blog/checking-concurrent-visitors-with-google-analytics/

https://support.google.com/analytics/answer/1006253?hl=en