node-gcm server receive error: MismatchSenderId - node.js

Question

I have some problems with my project, i hope you will help me!
Description:
I use library from https://github.com/ToothlessGear/node-gcm to build server push notification for some devices.
I have configured API key from Google Cloud Message to SenderId.
My code:
var message2 = new gcm.Message();
**// ... or some given values
var message2 = new gcm.Message({
collapseKey: 'demo',
delayWhileIdle: true,
timeToLive: 3,
data: {
key1: 'message1',
key2: 'message2'
}
});
// Change the message data
// ... as key-value
message2.addData('key1','message1');
message2.addData('key2','message2');
// ... or as a data object (overwrites previous data object)
message2.addData({
key1: 'message1',
key2: 'message2'
});
// Change the message variables
message2.collapseKey = 'demo';
message2.delayWhileIdle = true;
message2.timeToLive = 3;
message2.dryRun = true;
// Set up the sender with you API key
var sender = new gcm.Sender('AIzaSyBzb1PsEBEiAjagslkEANqyxxxxxxxxx');
// Add the registration IDs of the devices you want to send to
var registrationIds = [];
registrationIds.push('APA91bHAbFJYpHsSN-uz1Hkh8XjBw4xU87VIz5hZYOtobVv6I2pUZM67pWUGbb5zcP2HxXrooYiIOhzhIV7TuRDbVOlRDak-.xxxxxxxxxx');
sender.send(message2, registrationIds, 4, function(err, result) {
console.log(result);
});**
Then, I ran and recevied message as picture!

Answer 1

According to the documentation, MismatchSenderId means that the sender (API key) does not have access to send notifications to the registration ID:
A registration ID is tied to a certain group of senders. When a client app registers for GCM, it must specify which senders are allowed to send messages. You should use one of those sender IDs when sending messages to the client app. If you switch to a different sender, the existing registration IDs won't work.
You should make sure that your registration ID allows notification from the sender.