tiborp,
Thanks for getting in touch! Unfortunately, the Community events add-on doesn’t support being able to change the ‘/add’ part of the URL without modifying the core plugin files. You can change the ‘community’ slug to something else by going to ‘Events->Settings->Community’ and changing the option there (screenshot).
If this is something you’d like to see in a future release, I would suggest submitting it as an idea on our UserVoice page. Our team periodically reviews the most popular ideas for possible inclusion in a future release of the plugin.
Please let me know if you have further questions, and I’d be glad to help. Thanks! 🙂
-Casey-