How would i send my request at a specific unix time

Question

I am creating a minecraft name sniper that has to send a request at a specific unix time, how can i make it so that it waits until that time to send requests?

myrequests:

public async Task Put(string name)
        {
            var sent = DateTimeOffset.Now.ToUnixTimeMilliseconds();
            Console.WriteLine($"Sent:   {sent}");
            using (var request = new HttpRequestMessage(HttpMethod.Put, $"https://api.minecraftservices.com/minecraft/profile/name/{name}"))
            {
                request.Headers.Add("Authorization", "Bearer Token");
                using (var response = await client.SendAsync(request))
                {
                    var recv = DateTimeOffset.Now.ToUnixTimeMilliseconds();
                    Console.WriteLine($"Status Code:  {response.StatusCode}");
                    Console.WriteLine($"Recv:  {recv}");
                    Console.WriteLine();


                }
            }
        }