How to configure firebase cloud messaging to get push notifications

NEED HELP Regarding notifications: This is exactly my problem statement, but i would like to receive notifications using firebase cloud messaging
I was seeing this website that @Salman_Dev had shared in another post:
in this link, what i understand is that we can set a time to send notifications , but i would like to send them based on the value of sensors, how do i go abt doing that?

also saw

in this above link, what shd be the package name and what to do with the json file?

also how should the app be designed to use FCM feature, like should i store mobile numbers , e-mail ids

you mean like, the notification is not sent from you, so the notification is automatically when the user creates something?

Maybe you should look at this:

@Salman_Dev I'll explain my setup: I have arduino posting values of some sensors to firebase which can be monitored by the app. I want to send notifications to the mobile phone when the sensor values are abnormal. I had already gone through the link that you have suggested, it sends notification to phone based on time. i want the user to be notified when there's an abnormality!

You can use Extension Notification from this :

were you able to solve your problem? I'm in the same situation as you too