pythonのLineBotApiでImageSendMessageができない。

linebotのmessagingapiで指定されたテキストに対して画像を送信したいのですが、line上で指定のテキストを送るとエラーが出て、画像が送られません。どうすれば画像を送れるでしょうか。

Traceback (most recent call last):
  File "c:\anaconda3\envs\spyder4\lib\site-packages\flask\app.py", line 2073, in wsgi_app
    response = self.full_dispatch_request()
  File "c:\anaconda3\envs\spyder4\lib\site-packages\flask\app.py", line 1518, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "c:\anaconda3\envs\spyder4\lib\site-packages\flask\app.py", line 1516, in full_dispatch_request
    rv = self.dispatch_request()
  File "c:\anaconda3\envs\spyder4\lib\site-packages\flask\app.py", line 1502, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)   
  File "C:\Users\Name\Documents\Name\linebot.002\app.py", line 36, in callback     
    handler.handle(body, signature)
  File "c:\anaconda3\envs\spyder4\lib\site-packages\linebot\webhook.py", line 259, 
in handle
    self.__invoke_func(func, event, payload)
  File "c:\anaconda3\envs\spyder4\lib\site-packages\linebot\webhook.py", line 271, 
in __invoke_func
    func(event)
  File "C:\Users\Name\Documents\Name\linebot.002\app.py", line 62, in handle_message
    line_bot_api.reply_message(
  File "c:\anaconda3\envs\spyder4\lib\site-packages\linebot\api.py", line 109, in reply_message
    self._post(
  File "c:\anaconda3\envs\spyder4\lib\site-packages\linebot\api.py", line 1620, in 
_post
    self.__check_error(response)
  File "c:\anaconda3\envs\spyder4\lib\site-packages\linebot\api.py", line 1656, in 
__check_error
    raise LineBotApiError(
linebot.exceptions.LineBotApiError: LineBotApiError: status_code=400, request_id=XXXXXXXXXXXXXXX, error_response={"details": [{"message": "May not be empty", "property": "messages[0].previewImageUrl"}], "message": "The request body has 1 error(s)"}, headers={'Server': 'openresty', 'Date': 'Fri, 17 Dec 2021 22:53:09 GMT', 'Content-Type': 'application/json', 'Content-Length': '129', 'Connection': 'keep-alive', 'cache-control': 'no-cache, no-store, max-age=0, must-revalidate', 'expires': '0', 'pragma': 'no-cache', 'x-content-type-options': 'nosniff', 'x-frame-options': 'DENY', 'x-line-request-id': 'XXXXXXXXXXXXXXXXXXXXXXXXXX', 'x-xss-protection': '1; mode=block'}
127.0.0.1 - - [18/Dec/2021 07:53:04] "POST /callback HTTP/1.1" 500 -

↑以上のものが、テキストを送ると帰ってきます。app.pyのコードは以下の通りです。

from flask import Flask, request, abort

from linebot import (
    LineBotApi, WebhookHandler
)
from linebot.exceptions import (
    InvalidSignatureError
)
from linebot.models import (
    MessageEvent, TextMessage, TextSendMessage,ImageMessage,ImageSendMessage
)
from linebot.models.responses import Content
from werkzeug.datastructures import ContentSecurityPolicy
from werkzeug.wrappers import response

app = Flask(__name__)

line_bot_api = LineBotApi('XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX')
handler = WebhookHandler('XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX')

@app.route("/")
def test():
    return "OK"

@app.route("/callback", methods=['POST'])
def callback():
    # get X-Line-Signature header value
    signature = request.headers['X-Line-Signature']

    # get request body as text
    body = request.get_data(as_text=True)
    app.logger.info("Request body: " + body)

    # handle webhook body
    try:
        handler.handle(body, signature)
    except InvalidSignatureError:
        print("Invalid signature. Please check your channel access token/channel secret.")
        abort(400)

    return 'OK'


@handler.add(MessageEvent, message=TextMessage)
def handle_message(event):
    if event.message.text=="@start":
        orurl="https://drive.google.com/uc?id=ImageId"
        prurl="https://drive.google.com/uc?id=ImageId"
    line_bot_api.reply_message(
        event.reply_token,
        ImageSendMessage(
            original_content_url=orurl,
            preview_content_url=prurl))



if __name__ == "__main__":
    app.run()

python上でjsonのオブジェクトを使うなどしてみましたが、同じ結果でした。

バージョン情報: Windows 10 Home Python 3.8.12 64-bit('spyder4':conda) ngrok Windows(64-bit)