Flutter Firestore QuerySnapshot has no instance of getter 'documentID'

I get an error that "QuerySnapshot that has no instance of getter 'documentID'".

    StreamBuilder(
      stream: FirebaseFirestore.instance.collection("CHAT").orderBy("createdAt",descending: true).snapshots(),
      builder: (ctx,AsyncSnapshot snapshot){
        if(snapshot.connectionState==ConnectionState.waiting)
        {
           return  Center(child:  CircularProgressIndicator(color:Colors.green[300]));
        }
       else {
            var doc=snapshot.data!.docs;
            var user=FirebaseAuth.instance.currentUser;
            return ListView.builder(
              reverse: true,
              itemCount: doc.length,
              itemBuilder: (BuildContext ctx,index){
                 return BubbleMessage(
                   key: ValueKey(doc[index].documentID),
                   //:::::::::::::::get Message From firebase :::::::::::

                   message:doc[index]['message'],

                   //we check if the id isMe or the Other Person
                   isMe: doc[index]['userId']==user!.uid,

                   //::::::::::::::get  username From Firebase ::::::::::::::::::
                   username: doc[index]['username'],
 
          );
        },
             
     );

Why am I unable to access the documentID?