Understanding and Testing the PubSub+ Event Portal REST API

Is there any API approach to integrate in any existing API portal, reason behind my ask is : As part of digitalization most of the companies are moving towards APIs where I could see Event Driven , Async API’s are not have solid end to end access compare to REST, we are getting EDA related use cases and trying to derive those in API model, in that case base requirement is , enable all these solutions thorugh API’s . Was searching for that data and could not able to find…