First create a new account or property inside your google analytics dashboard this way for "joinnow.live"

Note: If you are using custom domain feature, please make sure to not use joinnow.live and instead use your own domain name. e.g. yourdomain.com

Once you get the "Tracking ID" copy that, and then go to your event editor, Miscellaneous > Google Analytics UA Number and insert the ID there.

Our system will send data from your webinar to your Google Analytics account now. You'll receive page-level data about each webinar page like Registration, Watch, and Thank You pages, in addition to event data like outbound clicks.