credentials used to authenticate does not have permission - node.js

Question

I am trying to use firebase cloud messaging to deploy a http push notifications onto an actual device. When so, I am getting the error
"The credential used to authenticate this SDK does not have permission to send messages to the device corresponding to the provided registration token. Make sure the credential and registration token both belong to the same Firebase project."
I have checked the credentials on both the frontEnd and backEnd side and they all match up with my firebase correctly. I have tried to follow plenty of examples on here and I have missed on all of them. My node.js file looks like
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
export GOOGLE_APPLICATION_CREDENTIALS = "/Users/myname/mylocation/myfile.json"
exports.sendPushNotifications = functions.https.onRequest((req, res) => {
res.send("Attempting to send push notification")
console.log("LOGGER --- Trying to send push message..");
var uid = 'randomUIDString'
var fcmToken = 'myToken'
return admin.database().ref('/users/' + uid).once('value', snapshot => {
var user = snapshot.val();
console.log("username is " + user.name);
var payload = {
notification: {
title: 'Push Notification Title',
body: 'Test Notification Message'
}
}
admin.messaging().sendToDevice(fcmToken, payload)
.then(function(response) {
console.log('Succesfully sent message:', response);
console.log(response.results[0].error);
})
.catch(function(error) {
console.log('Error sending message', error);
});
})
})
The users name prints from calling the uid, but I am having trouble accessing the fcmToken.
I have checked my info.plist and the correct project is listed. Same with apple developer and appDelegate. is there something more that I am missing??