Check out this thread. If you aren’t afraid of a little coding you can use Appdaemon to send text to this and it will output it on the desired alexa unit.
Right now, I have mine telling me when the back door is opened if it’s after we have set the nighttime mode at the house. I open the door and Alexa pops up and says “the back door is open, please remember to close and lock it when you are done”.