Currently doing the following, would be nice if the SDK provided a DisplayEvent enum and optionally a ReferenceId parser.
Placing more importance on the DisplayEventEnum.
const parsedEventParams = new URLSearchParams(
decryptedEvent.SaleToPOIRequest?.DisplayRequest?.DisplayOutput[0]?.OutputContent?.PredefinedContent?.ReferenceID,
);
// https://docs.adyen.com/point-of-sale/design-your-integration/notifications/display-notifications/#display-notification-types
parsedEventParams.get('event');