How can I get the number of followers (one of the insight properties) with Google-app-script linebot?

Question

I want to get the number of followers of my official account with a Google-app-script-made line bot in order to record it in a googlesheet. Here is part of my code:

if (messageText == "abc") {
              replyMsg(replyToken, [{
                "type": "text",
                "text": "The insight is" + insight(channelToken, 20220101).followers
              }] , channelToken);
            }

function replyMsg(replyToken, userMsg, channelToken) {
  var url = 'https://api.line.me/v2/bot/message/reply';
  var opt = {
    'headers': {
    'Content-Type': 'application/json; charset=UTF-8',
    'Authorization': 'Bearer ' + channelToken,
  },
  'method': 'post',
  'payload': JSON.stringify({
    'replyToken': replyToken,
      'messages': userMsg
   })
  };
  UrlFetchApp.fetch(url, opt);
}

function insight (channelToken, date) {
  var url = 'https://api.line.me/v2/bot/insight/followers?date={' + date + '}';
  var opt = {
    'headers': {
    //'Content-Type': 'application/json; charset=UTF-8',
    'Authorization': 'Bearer ' + channelToken,
  }
 };
 UrlFetchApp.fetch(url, opt);
}

Obviously it doesn't work correctly. How can I solve it? Thank you.

ksyt · Answer

You don't have to use '{' and '}' in the url. https://developers.line.biz/en/reference/messaging-api/#get-insight

Q&A

How can I get the number of followers (one of the insight properties) with Google-app-script linebot?