you need to enable registration on the event. you can also pull a report (under Admin\Account Management\Reports. FYI if you do not enable registration people need to fill out e-mail when they join the webinar, but this can be a fake e-mail. When registering people get an unique registatration link send to their e-mail. if you also enable authenticiation then the user must have a confirmed Zoom account. If this was helpful pls mark Accept as solution.