Hi folks,  sorry if some one answer it in the forum, but really, I did not find the info. 
How to send a single device a Push notification using Firebase. My humble understanding, I shall need the "FCM registration Token"
- How I can know that?
- If I know the FCM registration token, how to send a push notification to that single device.
I am thinking to develop or migrate my APP of B4A to B4I soon, and Iphone does not allow us to manage or handle the SMS arrived. So I will need to use FCM to integrate both Android APP and Iphone. put another layer
 to exchange info,   Thanks Steve jobs. 
 I cannot use SMS at all 
 between Android and Iphone.
			
			How to send a single device a Push notification using Firebase. My humble understanding, I shall need the "FCM registration Token"
- How I can know that?
- If I know the FCM registration token, how to send a push notification to that single device.
I am thinking to develop or migrate my APP of B4A to B4I soon, and Iphone does not allow us to manage or handle the SMS arrived. So I will need to use FCM to integrate both Android APP and Iphone. put another layer