https://stackoverflow.com/questions/61398980/error-type-eventlistener-does-not-take-parameters-implements-eventlistenerquer

I think many people stuck on this moment "Open the FirestoreAdapter class, which has been partially implemented already. First, let's make the adapter implement EventListener and define the onEvent function so that it can receive updates to a Firestore query:"

because of...

and there is no onEvent