This plugin allows you to easily extend event creation to anonymous users. These users will be required to provide their name, email address and you can also include a CAPTCHA code in order to submit an event for approval.
This plugin adds name, email and CAPTCHA code fields to your event creation form for non-logged in users.
You can choose between 3 types of CAPTCHA:
reCAPTCHA v2 (with full support to reCAPTCHA v2 options)
Joomla! CAPTCHA plugins
No CAPTCHA at all
Client and server side validation for any type of reCAPTCHA codes
Server side validation for all CAPTCHA codes
This specific extension can also be downloaded by itself from this page. Specific Download Page