How to solve Intent Redirection Vulnerability in android apk?

I created my app in Unity, then exported project and then I generated signed apk in Android Studio.

I wanted to upload my app to Google Play store, but it has been rejected because of security vulnerabilities.

The vulnerability is Intent Redirection and I was recommended to follow one of these steps: https://support.google.com/faqs/answer/9267555

My app uses firebase (db and auth) and I suppose that this could cause the vulnerability (but Im not sure, because my Alerts in Play Console are empty). But how can I fix this problem?

I tried to add android:exported=”false” to my Manifest file, but it only contains one activity, which is probably my whole app created in Unity. So when I added android:exported=”false” to this activity, I wasnt able to install my app (I found why Android Manifest's android:exported="false" prevents app from running on device)

My database manager looks like this:

public class DatabaseManager : MonoBehaviour 

{

public static DatabaseManager sharedInstance = null; private void Awake() { if (sharedInstance == null) { sharedInstance = this; } else if (sharedInstance != this) { Destroy(gameObject); } DontDestroyOnLoad(gameObject); FirebaseApp.DefaultInstance.SetEditorDatabaseUrl("https://addresstomydatabase.com/"); 

}