Ring door bell and Alexa echo dot

Hello Guys, I have problems with the use of the ring doorbell and Alexa echo dot . I followed this guide https://support.help.ring.com/hc/en-gb/sections/360006043651-Ring-Alexa- and everything is fine . I see the device connected in Alexa and everything seems fine . But if I try to push the button on the doorbell no sound exit from Alexa ! Other devices such smartphone works properly but Alexa doesn’t get the ring of the doorbell. Ideas ? Thank you