Arm Ring from Alexa

HiI'm trying to arm my Ring video doorbell and Ring Stick up cam from Alexa following this guide: https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://support.ring.com/hc/en-us/articles/360020893671-Arming-and-Disarming-Your-Ring-Devices-with-Alexa&ved=2ahUKEwjEwsuvwOOBAxU7Q_EDHYkQDT8QFnoECB4QAQ&usg=AOvVaw3arfmbr4HIHAfsyPEpigjdUnfortunately in the settings of my Ring devices inside the Alexa app there is no option to disarm by voice and then if I try to tell Alexa to Arm them it says that this feature is not supported by the device...What am I missing? Do only certain ring devices support arm/disarm from Alexa? I cannot find a list anywhere...ThanksRiccardo