So you are saying that your door sensor shows up in the Amazon app but the Alexa routine doesn’t work?
If so, that’s usually because there’s a very specific set of steps you need to go to in order to get Alexa to recognize the sensor for use in routines.
See the how to article in the community created wiki, go to the section on activating your device, and follow the steps there starting with step three in exactly the order written even if you think you have done some of them before.
(I know that section is talking about a virtual sensor, but just skip the first two steps and after that it’s the same for a physical sensor or a virtual sensor.)
That should get your routine working. 
As far as the notifications, I’ll leave other people to help you with that. Are you using the new V3 version of the app or the classic app?
FAQ: how to tell which version of the SmartThings mobile app that you have