Firebase Cloud Functions callable functions Unhandled error TypeError: Cannot read properties of undefined (reading 'auth')

Firebase CLI version: 12.4.0

Firebase Unity version: 11.2.0 (latest)

Unity: 2022.2.17

According to my understanding of firebase callable functions are that Firebase SDK automatically passes the context as parameter, but on server in my case auth is undefined and giving the following error

Unhandled error TypeError: Cannot read properties of undefined (reading 'auth')
    at /workspace/index.js:17:16
    at fixedLen (/workspace/node_modules/firebase-functions/lib/v2/providers/https.js:118:31)
    at /workspace/node_modules/firebase-functions/lib/common/providers/https.js:467:32
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

index.js

    const {onRequest, onCall, HttpsError} = require("firebase-functions/v2/https");
    const {initializeApp} = require("firebase-admin/app");

    initializeApp();

    exports.onLoginAddOTPEntry = onCall((data, context) => {
      console.log(data.otp);
      console.log(data.email);
      console.log(context);
    
      if (!data || !data.email || !data.otp) {
        throw new HttpsError("invalid-argument",
            "onLoginAddOTPEntry should be called with email and otp");
      }
    
      if (!context.auth) {
        throw new HttpsError(
            "unauthorized",
            "User is not authenticated",
        );
      }

      return "Worked!";
    });

Further debugging found out data and context, both are undefined somehow, while in Unity I debugged and logged the data is passed as it should be. Also, the user is logged in too. Here is my Unity C# calling code

private FirebaseFunctions firebaseFunctions;

public void Initialize()
{
    firebaseFunctions = FirebaseFunctions.DefaultInstance;
}

public async void CallableFunction(string functionName,
    KeyValuePair<string, string>[] dataToPass,
    Action<bool, string, string> _onSuccess)
{
    var function = firebaseFunctions.GetHttpsCallable(functionName);

    // pass data
    if (dataToPass?.Length > 0)
    {
        var data = new Dictionary<string, object>();
        for (int i = 0, count = dataToPass.Length; i < count; ++i)
        {
            data.Add(dataToPass[i].Key, dataToPass[i].Value);
        }

        await function.CallAsync(data).ContinueWith((task) =>
        {
            Debug.Log("Task: " + task.ToJSON());
        });
        return;
    }

    await function.CallAsync().ContinueWith((task) =>
    {
         Debug.Log("Task: " + task.ToJSON());
    });
}

NOTE: onRequest is working fine as expected, so variables and project ids are appropriately set too.

So what I'm doing wrong calling the callable onCall function?

> After adding more console.logs, found out no data is passed

Undefined
Undefined
Undefined

As you can see in the doc for Callable Cloud Functions 2nd generation the arguments passed to the callback function have changed from

1st gen: functions.https.onCall((data, context) => {...});

to

2nd gen: onCall((request) => {...});.

So you need to do:

exports.onLoginAddOTPEntry = onCall((request) => {

  const data = request.data;

  if (!data || !data.email || !data.otp) {
        throw new HttpsError("invalid-argument",
            "onLoginAddOTPEntry should be called with email and otp");
  }
    
  if (!request.auth) {
        throw new HttpsError(
            "unauthorized",
            "User is not authenticated",
        );
  }

  return "Worked!";
});