I am following the tutorial at: https://cloud.google.com/solutions/mobile/firebase-app-engine-android-studio
I have everything working and the email is sending every
Simple answer is you can't do that yet. Google cloud endpoints have a timeout of 1 min. Cron jobs also have a timeout.
What you need is triggers. This feature was demoed at Google io 16. Whenever data changes, a rest request is fired from firebase to a server and path of your choice.
Even I am waiting for this to arrive soon.