unity3d - Is it possible to only accept function calls from my app in Firebase?

Question

I am creating a game in Unity where the user can contribute with levels using a Level Creator system.

My application is setup in a way that I just need to call the Cloud Function with the level info, and it handles duplicate entries and saves it to Firestore. All of this works perfectly.

My question, basically, is: can I have my functions only accept calls from my game? (without having my users registered?).

Naturally, I am using functions.https.onCall((data, context) => {}). In the documentation for Firebase, I noticed they use context.auth to check whether the user is authenticated or not. However, I am logging this value to the console and it appears to be undefined.

I am also confused with this line, from the same link:

With callables, Firebase Authentication and FCM tokens, when available, are automatically included in requests.

Maybe context.auth is not defined because my game isn't yet in Google Play / Apple Store? Any ideas?

Answer 1

Waitting for answers