FCM notification 4.1

Hello, i updated my Traccar to 4.1 to use FCM that I was waiting since a long time, but I can not find how to add FCM in the config.xml file could you help me please.
A big thanks for all the hard work you are doing.

You need to add something like this to the config file:

<entry key='notificator.firebase.key'>FIREBASE_KEY_GOES_HERE</entry>

The trick is that you need corresponding mobile apps.

Thanks for your quick answer
When you say I need the corresponding mobile app you mean the one that is in your website or I need to modify your app also?
Thanks

To send push notifications to a mobile app you need a Firebase key, which corresponds to same Firebase project as mobile apps. Official apps include our keys, but obviously we can't share key for the server. You would need your own apps with own firebase keys.