The RKD API team informed me that you already contacted them and the team has provided the following information for you.
You can find the dividend information in the RKD Street Event V2 service's Get Event Headlines operation.
Once you have the results it will show the list of events with the event ID. To get the dividend info you need to use event ID on get event service
Please be informed that the Q&A forum is for Refinitiv API general usage questions. If you have more RKD content questions, you can contact the RKD team via https://my.refinitiv.com/ website directly.
RKD API has various types of data and services. You can check the RKD API Catalog page to find the list of all available services in detail.
Regarding the API data coverage, you can check each service FactSheet and Data coverage in the RKD API download page.
Hope this helps.