Telegram Bot - how to get a group chat id?

Question

I\'ve been using telegram_bot, and trying to get groupChat id to send notifications to group chat, but don\'t know which methods I have to use for it.

For getting ch

Answer 1

bot receives the following message originated on a Telegram group having a bot co-existing:

extract data as required

function doPost(e) {
    var contents = JSON.parse(e.postData.contents);
    //  GmailApp.sendEmail(Session.getEffectiveUser().getEmail(), "Telegram Bot Update", JSON.stringify(contents, null, 4));
    var chat_id = contents.message.chat.id;
    var text = contents.message.text;
    var name = contents.message.from.first_name + " " +  contents.message.from.last_name;
    var sResponse = telegramBotMachine( chat_id, text, name );
}  

/* contents

{
    "update_id": 20383255,
    "message": {
        "message_id": 147,
        "from": {
            "id": 999999999,
            "is_bot": false,
            "first_name": "Trajano",
            "last_name": "Roberto",
            "username": "TrajanoRoberto",
            "language_code": "en"
        },
        "chat": {
            "id": -666666666,
            "title": "Test Ataque Media Flamengo",
            "type": "group",
            "all_members_are_administrators": true
        },
        "date": 1585450075,
        "text": "Menu"
    }
}