Error Target of URI doesn't exist: 'package:cloud_firestore/cloud_firestore.dart'.

import 'dart:convert';
import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:intl/intl.dart';
import 'package:timeago/timeago.dart' as timeago;
import '/flutter_flow/lat_lng.dart';
import '/flutter_flow/place.dart';
import '/flutter_flow/uploaded_file.dart';
import '/flutter_flow/custom_functions.dart';
import '/backend/backend.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import '/auth/firebase_auth/auth_util.dart';

List<double> getMonthlySumByCategory(String? category) {
  /// MODIFY CODE ONLY BELOW THIS LINE

  // Retieve all AMOUNT values for a particular category  for current month from EXPENSE collection and return the list
  List<double> amounts = [];

  // Get the current month and year
  DateTime now = DateTime.now();
  int currentMonth = now.month;
  int currentYear = now.year;

  // Query the EXPENSE collection for the current month and category
  // Assuming expense collection is a Firestore collection
  FirebaseFirestore.instance
      .collection('EXPENSE')
      .where('category', isEqualTo: category)
      .where('month', isEqualTo: currentMonth)
      .where('year', isEqualTo: currentYear)
      .get()
      .then((QuerySnapshot querySnapshot) {
    querySnapshot.docs.forEach((doc) {
      // Get the amount value and add it to the list
      double amount = doc['amount'] ?? 0.0;
      amounts.add(amount);
    });
  });

  return amounts;

  /// MODIFY CODE ONLY ABOVE THIS LINE
}