function doPost(e) {
  var ssId = "<Your Google Sheet ID>";
  var ss = SpreadsheetApp.openById(ssId);
  var sheetData1 = ss.getSheetByName("data1");
  var sheetData2 = ss.getSheetByName("data2");

  //use BetterLog
  Logger = BetterLog.useSpreadsheet(ssId);

  //Logger.log("Hello from BetterLog :)");

  var requestJSON = e.postData.contents;
  Logger.log(requestJSON);
  
  var requestObj = JSON.parse(requestJSON).events[0];
  var userMessage = requestObj.message.text;
  Logger.log(userMessage);
  
  var token = requestObj.replyToken;
  var replyText = userMessage;
  
  if (requestObj.message.type === "text") {
  
    replyMessage(token, replyText);
    
  }
}

// Reply message to Line
function replyMessage(token, replyText) {
  var url = "https://[Log in to view URL]";
  var lineHeader = {
    "Content-Type": "application/json",
    "Authorization": "Bearer <Your Channel Access Token>"
  };

  var postData = {
    "replyToken" : token,
    "messages" : [{
      "type" : "text",
      "text" : replyText
    }]
  };

  var options = {
    "method" : "POST",
    "headers" : lineHeader,
    "payload" : JSON.stringify(postData)
  };

  try {
    var response = UrlFetchApp.fetch(url, options);
  }
  
  catch (error) {
    Logger.log(error.name + "：" + error.message);
    return;
  }
    
  if (response.getResponseCode() === 200) {
    Logger.log("Sending message completed.");
  }
}