Telegram bot get all messages

I made a telegram bot, received a token from it and now made it an administrator. How can I get through the bot all messages from the moment it was added? There are requests in this group and I need to get their full text.

https://api.telegram.org/bot<token>/getUpdates

{
    "ok": true,
    "result": [
        {
            "update_id": 523188842,
            "message": {
                "message_id": 3,
                "from": {
                    "id": 1087333324,
                    "is_bot": true,
                    "first_name": "Group",
                    "username": "GroupBot"
                }, 

             "sender_chat": {
                "id": -10021999992,
                "title": TITLE",
                "type": "supergroup"
            },

}

I receive a response after a getUpdate request, it contains the chat id and title, but how can I get the full text of the messages?