Zoom - Allowing only authenticated users in meetings

To enable or disable Only authenticated users can join meetings for your own use:

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Settings.
3. Click the Meeting tab.
4. Under Security, click the Only authenticated users can join meetings toggle to enable or disable it.
5. If a verification dialog appears, click Enable or Disable to verify the change.
    

Source - https://support.zoom.com/hc/en/article?id=zm_kb&sysparm_article=KB0063018