Trying to figure out how to customize data that is retrieved through Ajax

Summary:

I am creating a custom widget to get my related answers, based on the standard OkcsRelatedAnswers-widget. We just upgraded to framework 3.9 and in 3.8 I could just get my data through my controller and present it. Since framework 3.9 I can still use my controller to get and change my data, but the data for viewing the widget is passed through Ajax.

In the model I can see an there is a call to an OkcsApi->getRelatedAnswers, but I do not know where to find this.

In my controller I pass an extra parameter for the ProductID, because in this particular interface a user gets a fixed ProductID.