Capatcha for submit-your-event Site

at the moment that is not included in the event submission form however maybe you can modify it’s template file template/forms/event-editor.php

to use template: https://wp-events-plugin.com/documentation/using-template-files/

I think this could go but I’m missing something here knowledge

maybe this can give you an idea – https://pastebin.com/7SNMphtu

Would you make any adjustments if I had Pro support?

sorry Pro support doesn’t cover custom jobs like this, try htpp://jobs.wordpress.net

assuming the example snippet above works, it’d be a small task to implement