Nó FCM
var FCM = require('fcm-node');
var serverKey = 'YOURSERVERKEYHERE'; //put your server key here
var fcm = new FCM(serverKey);
fcm.subscribeToTopic([ 'device_token_1', 'device_token_2' ], 'some_topic_name', (err, res) => {
assert.ifError(err);
assert.ok(res);
done();
});
Bhavik Maheta