I use the eventbutton plugin from earlier JEM3 on JEM 2.2 with Joomla 3.6.5 and php 7.1.
I can choose in FE events which are then linked in an article.
Even when it works, I get some error notifications in the modal window.
on JEM 2.3.0 stable in latest Joomla (3.9.22) Protostar php7.4.5