line botのline messeging apiでのエラーについて(python)

前提・実現したいこと

pythonで食べログのサイトから新店舗を持ってくるlinebotを作っています。

エラーメッセージ
2020-03-08T13:04:03.229498+00:00 app[web.1]: [2020-03-08 13:04:03,228] ERROR in app: Exception on /callback [POST]
2020-03-08T13:04:03.229518+00:00 app[web.1]: Traceback (most recent call last):
2020-03-08T13:04:03.229519+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/flask/app.py", line 2446, in wsgi_app
2020-03-08T13:04:03.229519+00:00 app[web.1]: response = self.full_dispatch_request()
2020-03-08T13:04:03.229520+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/flask/app.py", line 1951, in full_dispatch_request
2020-03-08T13:04:03.229521+00:00 app[web.1]: rv = self.handle_user_exception(e)
2020-03-08T13:04:03.229521+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/flask/app.py", line 1820, in handle_user_exception
2020-03-08T13:04:03.229523+00:00 app[web.1]: reraise(exc_type, exc_value, tb)
2020-03-08T13:04:03.229523+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
2020-03-08T13:04:03.229524+00:00 app[web.1]: raise value
2020-03-08T13:04:03.229524+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/flask/app.py", line 1949, in full_dispatch_request
2020-03-08T13:04:03.229525+00:00 app[web.1]: rv = self.dispatch_request()
2020-03-08T13:04:03.229525+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/flask/app.py", line 1935, in dispatch_request
2020-03-08T13:04:03.229526+00:00 app[web.1]: return self.view_functions[rule.endpoint](**req.view_args)
2020-03-08T13:04:03.229527+00:00 app[web.1]: File "/app/app.py", line 49, in callback
2020-03-08T13:04:03.229527+00:00 app[web.1]: handler.handle(body, signature)
2020-03-08T13:04:03.229528+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/linebot/webhook.py", line 260, in handle
2020-03-08T13:04:03.229528+00:00 app[web.1]: func(event)
2020-03-08T13:04:03.229529+00:00 app[web.1]: File "/app/app.py", line 64, in handle_message
2020-03-08T13:04:03.229530+00:00 app[web.1]: line_bot_api.reply_message(event.reply_token,TextSendMessage(text="キーワードを入力してください(入力例:ラーメン,スイーツなど)"))
2020-03-08T13:04:03.229530+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/linebot/api.py", line 107, in reply_message
2020-03-08T13:04:03.229531+00:00 app[web.1]: '/v2/bot/message/reply', data=json.dumps(data), timeout=timeout
2020-03-08T13:04:03.229531+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/linebot/api.py", line 996, in _post
2020-03-08T13:04:03.229531+00:00 app[web.1]: self.__check_error(response)
2020-03-08T13:04:03.229532+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.7/site-packages/linebot/api.py", line 1022, in __check_error
2020-03-08T13:04:03.229532+00:00 app[web.1]: error=Error.new_from_json_dict(response.json)
2020-03-08T13:04:03.229536+00:00 app[web.1]: linebot.exceptions.LineBotApiError: LineBotApiError: status_code=400, request_id=62c5c949-417b-4e7a-9fff-fad14efacd75, error_response={"details": [], "message": "Invalid reply token"}, headers={'Server': 'nginx', 'Content-Type': 'application/json', 'x-line-request-id': '62c5c949-417b-4e7a-9fff-fad14efacd75', 'x-content-type-options': 'nosniff', 'x-xss-protection': '1; mode=block', 'x-frame-options': 'DENY', 'Content-Length': '33', 'Expires': 'Sun, 08 Mar 2020 13:04:03 GMT', 'Cache-Control': 'max-age=0, no-cache, no-store', 'Pragma': 'no-cache', 'Date': 'Sun, 08 Mar 2020 13:04:03 GMT', 'Connection': 'close'}
2020-03-08T13:04:03.246407+00:00 app[web.1]: 10.150.246.196 - - [08/Mar/2020:13:04:03 +0000] "POST /callback HTTP/1.1" 500 290 "-" "LineBotWebhook/1.0

### 該当のソースコード
import urllib.request
import os
import sys
import json
from argparse import ArgumentParser
 
from flask import Flask, request, abort
from linebot import (
    LineBotApi, WebhookHandler
)
from linebot.exceptions import (
    InvalidSignatureError
)
from linebot.models import (
    MessageEvent, TextMessage, TextSendMessage,
)

import scrape
 
app = Flask(__name__)
 
channel_secret = os.getenv('LINE_CHANNEL_SECRET', None)
channel_access_token = os.getenv('LINE_CHANNEL_ACCESS_TOKEN', None)
if channel_secret is None:
    print('Specify LINE_CHANNEL_SECRET as environment variable.')
    sys.exit(1)
if channel_access_token is None:
    print('Specify LINE_CHANNEL_ACCESS_TOKEN as environment variable.')
    sys.exit(1)
 
line_bot_api = LineBotApi(channel_access_token)
handler = WebhookHandler(channel_secret)
jyanru = ""
basyo = ""

@app.route("/")
def hello_world():
    return "hello world!"
 
@app.route("/callback", methods=['POST'])
def callback():
    signature = request.headers['X-Line-Signature']
 
    body = request.get_data(as_text=True)
    app.logger.info("Request body: " + body)
 
 
    try:
        handler.handle(body, signature)
    except InvalidSignatureError:
        abort(400)
 
    return 'OK'

@handler.add(MessageEvent, message=TextMessage)
def handle_message(event):
    flag = 0
    if event.reply_token == "00000000000000000000000000000000":
        return
    if event.message.text != "":
        line_bot_api.reply_message(event.reply_token,TextSendMessage(text="エリアを入力してください(入力例:赤坂,東京など)"))
        flag += 1
    if event.message.text != "" and flag == 1:
        line_bot_api.reply_message(event.reply_token,TextSendMessage(text="キーワードを入力してください(入力例:ラーメン,スイーツなど)"))
        basyo = event.message.text
        flag += 1
    if event.message.text != "" and flag == 2:
        jyanru = event.message.text
        results = scrape.main(basyo,jyanru)
        line_bot_api.reply_message(event.reply_token,TextSendMessage(text=results))
    else:
        line_bot_api.reply_message(event.reply_token,TextSendMessage(text="最初からやり直してください"))
        return

if __name__ == "__main__":
    #port = int(os.getenv("PORT", 8000))
    app.run()#host="0.0.0.0", port=port)

```ここに言語名を入力
python
### 試したこと

scrape側のchromedriverの接続、webhookの検証、herokuでのオフライン確認(hroku open)はうまくいっています。

### 補足情報（FW/ツールのバージョンなど）
最初のメッセージは出るのですが次のメッセージでエラーが出てしまいます。