want to ask how i can add a search from firestore and display it I am trying but it is not working with me

I tried to make methods and import but it’s not working here is the method I used

import 'package:cloud_firestore/cloud_firestore.dart';  class SearchService {   searchByName(String searchField) {     return FirebaseFirestore.instance         .collection('Names')         .where('name',         isEqualTo: searchField.substring(0, 1).toUpperCase())         .get();   } }