Get Invite_link by getUpdates method Telegram-API

Question

I want to know the link which was used by the user to join the group and I try to get the invite_link derived from this variable :

But, when I used getUpdates() method to receive incoming updates (Update is the object on which ChatMemberUpdated is),it didn't include invite_link.

This is the code (nodejs):

await client.getUpdates({ offset : 0, allowed_updates : 'chat_member' }).then(async function(update) {
    console.log(update)
    if (update.length != 0){
        fs.appendFile('update.txt', JSON.stringify(update), function (err) {
            if (err) throw err
            console.log('Saved!')
        })
    }
})

And this is the result:

[{"update_id":xx96xxxxx,"message":{"message_id":2xxxx,"from":{"id":x669xxxxxx,"is_bot":false,"first_name":"xx.nwxxx","language_code":"es"},"chat":{"id":-xxxx4506xxxxx,"title":"xxxxxxx","type":"supergroup"},"date":xxx195xxxx,"new_chat_participant":{"id":xxx9660xxx,"is_bot":false,"first_name":"xxxnwxxx","language_code":"es"},"new_chat_member":{"id":xxx9660xxx,"is_bot":false,"first_name":"xxxnwxxx","language_code":"es"},"new_chat_members":[{"id":xxx9660xxx,"is_bot":false,"first_name":"xxxnwxxx","language_code":"es"}]}}]

Answer 1

At the moment to create the invite_link, you need to specified "creates_join_request" as true. Otherwise, the bot cannot detect the link.