Google apps scriptで図書館のホームページにログインしたいのですが、できません。
どうすればログインできるのでしょうか？

function myFunction() {
var payload = {
"username" : "XXXXXXXXXX",
"j_password" : "XXXXXXX",
}
var options = {
"method" : "POST",
"payload" : payload,
"followRedirects" : false
}
var url = "https://opac.toshokan.city.fukuoka.lg.jp/licsxp-opac/j_security_check?subSystemFlag=0";

var response = UrlFetchApp.fetch(url, options);
var cookies = response.getHeaders()["Set-Cookie"];
var headers = { 'Cookie' : cookies };
options = {
method : "get",
headers : headers,
followRedirects: true,
};
var topUrl = "https://opac.toshokan.city.fukuoka.lg.jp/licsxp-opac/WOpacUsrLendListAction.do";
response = UrlFetchApp.fetch(topUrl, options);
var content = response.getContentText("UTF-8");
Logger.log(content)
}