As you may know, the board managing the core my Alarm set of devices is a Wemos D1 mini. The libraries I tried to received RF 433Mhz were not compatible with this wifi board. Indeed, RadioHead throws an exception for an unknown reason. VirtualWire was designed to work on AVR processors.
Thus, I changed to RC-Switch library. Need to know : only send/received numbers or binary coded data, no strings. But it works perfectly on the Wemos D1 mini. I got help from a site I visite quite often to implement the code : random nerd. Result both the emitter and the receiver communicate nicely.
Then, after several hours, let’s say days, I got the notification sent to my phone through the Firebase API. First, you’ll need to create an app in Firebase and then set the notification service according to your device (iOS / Android). Maybe the most difficult part but fully works, so check my github below for proper iOS code.
I also experimented pushing data from Arduino IDE (Wemos board) to the database of my Firebase app. Nothing hard, check my code as well.