You probably did not add package or did not get it.

add in following way.

dependencies:
  html: ^0.14.0+3

Now run following command in terminal:

flutter pub get

i’m have tried using package Parser HTML with Flutter but i’m tried compile, this error is returned:

import 'package:flutter/material.dart';
import 'package:scrapy/scrapy.dart';
import 'package:html/parser.dart' as html;

Compiler message:
Error: Could not resolve the package 'html' in 'package:html/parser.dart'.
lib/main.dart:3:8: Error: Not found: 'package:html/parser.dart'
import 'package:html/parser.dart' as html;

Only html parser is wrong