fetch the data from firebase and populate the recyclerview through for loop if the keys of the node are stored locally

Question

I have the list of items in one node and in another node, I want to store the key of items that user like. Now through callBack I got all the keys stored in the favorite node and I am trying to search the data of that key which is stored in the allItems node and populate the recyclerView something like this

My Code

// Here I successfully got all the keys in lyKey
for(ItemsExploreModel keys : ltKey)
{
    // Toast.makeText(getContext(), keys.getKey(), Toast.LENGTH_SHORT).show();
    mDatabase.getReference().child(FirebaseVar.ALLITEMS).child(keys.getKey()).addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot2) {
            if (snapshot2.exists())
            {
                ItemsExploreModel adp = snapshot2.getValue(ItemsExploreModel.class);
                ItemsExploreModel adp2 = new ItemsExploreModel(snapshot2.getKey());


                list.add(adp);
                listKey.add(adp2);
            }

        }

        @Override
        public void onCancelled(@NonNull DatabaseError error) {

        }
    });
}

Now problem is it exactly show the Toast but sometimes load the data and sometimes not I don't know why.May be it is because Async task because one key is not loaded and it goes for another key to load in for loop. And I marked that if I don't put Toast here then it not at all shows any item but if I put Toast then sometimes it shows. All solutions will be appreciated.