Can't resolve problems with Firebase integration on flutter

Hello, I’m trying to connect RevenueCat → FireBase integration and I have several errors and no understanding 

1. When I use LogIn(Firebase Analytics ID), I have an error:
   Invalid API Key., readable_error_code: INVALID_CREDENTIALS, message: There was a credentials issue
2. I just skipped this step and just connect Firebase ID:
   FirebaseAnalytics analytics = FirebaseAnalytics.instance;
   purchases.Purchases.setFirebaseAppInstanceId(instanceID);
3. But then I receive events from RC only from Android, no ios 

So possible it’s a some bug with a Flutter for Firebase integration. I haven’t found a solution

The next problem is that RC events to Firebase is “purchase” for Cancelation, Purchase, Error etc. But how to understand if the user bought a Lifetime subscription? Yes, I can get rc_trial_start event for Trials, but how to get it for just purchases? I can’t use it for Google Ads for example

Would love to receive a help!