Hi @Dar Kronenblum,
I'm not entirely sure what you are trying to achieve, but you don't need an API to publish events in Jira itself. Triggering custom events from within Jira Cloud is built in. Maybe this support article is a good starting point, if you want to trigger events from workflows.
Apart from that, the also built-in automation for Jira offers a lot of out-of-the-box actions to integrate with other systems. They allow you to send slack messages, create branches, send emails or even more generically send a web request.
Hope this helps!