How does a simple while loop work in the telegram api example?

Question

C++ / C#

I deal with an example on a telegram bot. Tell me if I understand the work of the following code correctly, or rather, even the cycle itself.
Initially, the update_id = 0 variable was declared. If my last message's update_id is 969654771, it turns out that the loop runs the following line 969654771 times:

string url = $"{startUrl}/getUpdates?offset={updateid + 1}"

until it reaches this number? Do I understand correctly?

int update_id = 0;
            string messageFromId = "";
            string messageText = "";
            string token = "540661148";

            WebClient webclient = new WebClient();
            string startUrl = $"https://api.telegram.org/bot{token}";


            while(true)
            {
                string url = $"{startUrl}/getUpdates?offset={update_id + 1}";
                string response = webclient.DownloadString(url);

             }

Answer 1

If my update_id of the last post is 969654771,

Show with your finger, where is the check for this condition in the code?
And no, the code works completely differently.