In addition to allowing anonymous event submission, you also need to set the default user for anonymous event submission and that user must have a role with permission to submit events.
You can set the user role capabilities by going to Event > Settings and then select User Capabilities in the General tab.
Thanks for the prompt response. It’s much appreciated.
However, there is no ‘submit events’ option in the user roles. If I use the ‘publish events’ option the event is published without being held for approval.
I created a new user called Anonymous and gave them the Contributor role. When I created an event in an Incognito window it was not published but remained in the Pending state: