Hi neighbors! You cannot have the siren on your Cameras sound automatically when motion is detected. If you have a Ring Alarm system, you can use the Linked Devices feature to link your Cameras to your Ring Alarm so that the sirens will be triggered when the alarm is triggered.
Feel free to also add your feedback and vote to the feature request about having the siren on your Camera sound automatically with motion detection. We utilize the Feature Request board to gather and share your feedback with our teams here. 